Populism, defined either as an ideology (more rarely and uncommonly), a political philosophy or a type of discourse, is a type of political-social thought which juxtaposes "the people" against "the elites", and urges social and political system changes. It can also be defined as a rhetorical style deployed by members of political or social movements. It is defined by the Cambridge dictionary as "political ideas and activities that are intended to represent ordinary people's needs and wishes". 
Academic and scholarly definitions of populism vary widely and the term is often employed in loose, inconsistent and undefined ways to denote appeals to ‘the people’, ‘demagogy’ and ‘catch-all’ politics or as a receptacle for new types of parties whose classification is unclear. A factor held to diminish the value of ‘populism’ in some societies is that, as Margaret Canovan notes in her 1981 study Populism, unlike labels such as ‘conservative’ or ‘socialist’, the meanings of which have been ‘chiefly dictated by their adherents’, contemporary populists rarely call themselves ‘populists’ and usually reject the term when it is applied to them by others . Some exceptions to this pattern of pejorative usage exist, notably in the United States, but it appears likely that this is due to the memories and traditions of earlier democratic movements (for example, farmers' movements, New Deal reform movements, and the civil rights movement) that were often called populist, by supporters and outsiders alike. It may also be due to linguistic confusions of populism with terms such as "popular" .
Due to the attention on populism in the academic world, scholars have made advances in defining the term in ways which can be profitably employed in research and help to distinguish between movements which are populist and those which simply borrow populist ideas. One of the latest definitions of populism comes from Daniele Albertazzi and Duncan McDonnell who, in their volume Twenty-First Century Populism, define populism as "an ideology which pits a virtuous and homogeneous people against a set of elites and dangerous ‘others’ who are together depicted as depriving (or attempting to deprive) the sovereign people of their rights, values, prosperity, identity and voice" . Rather than viewing populism in terms of specific social bases, economic programs, issues or electorates, as discussions of right-wing populism have tended to do, this conception of populism belongs to the tradition of scholars such as Ernesto Laclau, Pierre-Andre Taguieff, Yves Meny and Yves Surel who have all sought to focus on populism per se, rather than simply as an appendage of other ideologies such as nationalism or neo-liberalism. Given its central tenet that democracy should reflect the pure and undiluted will of the people, populism can sit easily with ideologies of both right and left. While leaders of populist movements in recent decades have claimed to be on either the left or the right of the political spectrum, many populists claim to be neither "left wing," "centrist" nor "right wing."
Some scholars argue that populist organizing for empowerment represents the return of older "Aristotelian" politics of horizontal interactions among equals who are different, for the sake of public problem solving . Populism has taken left-wing, right-wing, and even centrist forms, as well as forms of politics that bring together groups and individuals of diverse partisan views. The use of populist rhetoric in the United States has recently included references such as "the powerful trial lawyer lobby", "the liberal elite," or "the Hollywood elite". An example of populist rhetoric on the other side of the political spectrum was the theme of "Two Americas" in the 2004 Presidential Democratic Party campaign of John Edwards.
Populists are seen by some politicians as a largely democratic and positive force in society, while a wing of scholarship in political science contends that populist mass movements are irrational and introduce instability into the political process. Margaret Canovan argues that both these polar views are faulty, and has defined two main branches of modern populism worldwide — agrarian and political — and mapped out seven disparate sub-categories:
It is believed by some that populist movements can be precursors for, or building blocks for, fascist movements. Conspiracist scapegoating employed by various populist movements can create "a seedbed for fascism." National socialist populism interacted with and facilitated fascism in interwar Germany. In this case, distressed middle–class populists during the pre-Nazi Weimar period mobilized their anger at government and big business. The Nazis "parasitized the forms and themes of the populists and moved their constituencies far to the right through ideological appeals involving demagoguery, scapegoating, and conspiracism." According to Fritzsche:
The Nazis expressed the populist yearnings of middle–class constituents and at the same time advocated a strong and resolutely anti-Marxist mobilization....Against "unnaturally" divisive parties and querulous organized interest groups, National Socialists cast themselves as representatives of the commonwealth, of an allegedly betrayed and neglected German public....[b]reaking social barriers of status and caste, and celebrating at least rhetorically the populist ideal of the people’s community...
The word populism is derived from the Latin word populus, which means people in English (in the sense of "nation," as in: "The Roman People" (populus Romanus), not in the sense of "multiple individual persons" as in: "There are people visiting us today"). Therefore, populism espouses government by the people as a whole (that is to say, the masses). This is in contrast to elitism, aristocracy, synarchy or plutocracy, each of which is an ideology that espouse government by a small, privileged group above the masses.
Populism has been a common political phenomenon throughout history. The Populares were an unofficial faction in the Roman senate whose supporters were known for their populist agenda. Some of the most well known of these were Tiberius Grachus, Gaius Marius, Julius Caesar and Caesar Augustus, all of whom eventually used referendums to bypass the Roman Senate and appeal to the people directly.
Populism rose during the Reformation; Protestant groups like the Anabaptists formed ideas about ideal theocratic societies, in which peasants would be able to read the Bible themselves. Attempts to establish these societies were made during the Peasants' War (1524–1525) and the Münster Rebellion (1534–1535). The peasant movement ultimately failed as cities and nobles made their own peace with the princely armies, which restored the old order under the nominal overlordship of the Holy Roman Emperor Charles V, represented in German affairs by his younger brother Ferdinand.
The same conditions contributed to the outbreak of the English Revolution of 1642–1651, also known as the English Civil War. Conditions led to a proliferation of ideologies and political movements among peasants, self-employed artisans, and working class people in England. Many of these groups had a dogmatic Protestant religious bent. They included Puritans and the Levellers.
Romanticism, the anxiety against rationalism, broadened after the beginnings of the European and Industrial Revolutions because of cultural, social, and political insecurity. Romanticism led directly to a strong popular desire to bring about religious revival, nationalism and populism. The ensuing religious revival eventually blended into political populism and nationalism, becoming at times a single entity and a powerful force of public will for change. This paradigm shift was marked by people looking for security and community because of a strong emotional need to escape from anxiety and to believe in something larger than themselves.
The revival of religiosity all over Europe played an important role in bringing people to populism and nationalism. In France, François-René de Chateaubriand provided the opening shots of Catholic revivalism as he opposed enlightenment's materialism with the "mystery of life," the human need for redemption. In Germany, Friedrich Daniel Ernst Schleiermacher promoted pietism by stating that religion was not the institution, but a mystical piety and sentiment with Christ as the mediating figure raising the human consciousness above the mundane to God's level. In England, John Wesley's Methodism split with the Anglican church because of its emphasis on the salvation of the masses as a key to moral reform, which Wesley saw as the answer to the social problems of the day.
Chateaubriand's beginning brought about two Catholic Revivals in France: first, a conservative revival led by Joseph de Maistre, which defended ultramontanism, which is a religious philosophy placing strong emphasis on the supremacy of the Pope, and a second populist revival led by Felicite de Lamennais, an excommunicated priest. This religious populism opposed ultramontanism and emphasized a church community dependent upon all the people, not just the elite. It stressed that church authority should come from the bottom up and that the church should alleviate suffering, not merely accept it. Both of these religious principles are based on populism.
Populism has been an important force in Latin American political history, where many charismatic leaders have emerged since the beginning of the 20th century. Populism in Latin America has been traced by some to concepts taken from Perón's Third Position. Latin American countries have not always had a clear and consistent political ideology under populism. Populist practitioners in Latin America usually adapt politically to the prevailing mood of the nation, moving within the ideological spectrum from left to right many times during their political lives. Most of these countries cannot be as clearly and easily divided between liberals and conservatives, as in the United States, or between social democrats and Christian democrats as in European countries. The more recent pattern that has emerged among Latin American populists has been socialist populism that appeals to masses of poor by promising redistributive policies and state control of the nation's energy resources.
Populism has been fiscally supported in Latin America during periods of growth such as the 1950s and 1960s and during commodity price booms such as in oil and precious metals. Political leaders could gather followers among the popular classes with broad redistributive programs during these boom times. Populism in Latin America has been sometimes criticized for the fiscal policies of many of its leaders, but has also been defended for having allowed historically weak states to alleviate disorder and achieve a tolerable degree of stability while initiating large-scale industrialization. Though specific populist fiscal and monetary policies may be criticized by economic historians, populism has allowed leaders and parties to co-opt the radical ideas of the masses so as to redirect them in a non revolutionary direction.
Often adapting a nationalist vocabulary and rhetorically convincing, populism was used to appeal to broad masses while remaining ideologically ambivalent. Notwithstanding, there have been notable exceptions. 21st Century Latin-American populist leaders have had a decidedly socialist bent.
When populists take strong positions on economic philosophies such as capitalism versus socialism, the position sparks strong emotional responses regarding how best to manage the nation's current and future social and economic position. Mexico's 2006 Presidential election was hotly debated among supporters and opponents of populist candidate Andrés Manuel López Obrador.
Populism in Latin American countries has both an economic and an ideological edge. The situation is similar in many countries with legacies of poor and low-growth economies. These conditions have led to highly unequal societies in which people are divided between a relative few wealthy families and masses of poor (with some exceptions such as Argentina, where strong and educated middle classes are a significant segment of the population).
Other perspectives trace inequality to the formation of Latin America's governments and institutions, which were shaped by the Spanish crown upon the Spanish colonization of the Americas. Latin America was not meant to be a colony for the settlers to live in and develop, like the United States, but a source of resources for the Spanish crown. After nations obtained their independence, many negative colonial social legacies survived.
Populists can be very successful political candidates in such countries. In appealing to the masses of poor people prior to gaining power, populists may promise widely-demanded food, housing, employment, basic social services, and income redistribution. Once in political power, they may not always be financially or politically able to fulfill all these promises. However, they are very often successful in providing many broad and basic services.
In Mexico, Brazil and Argentina, in a relatively short period of time, populist leaders were perceived to have delivered more to their lower class constituents than previous governments. Critics of populist policies point to the consequences of spending and lack of reform on these countries' respective finances, such as growing debt, pressured currencies, and hyperinflation, which in turn led to high interest rates, low growth, and a debt crisis. The 1980s in Latin America became referred to as a lost decade during which the region experienced low economic growth and few if any reductions in poverty while the Asian Tigers had been consistently developing through high rates of savings, investments, and educational achievements. Supporters of past economic policies would point to the uncontrollable economic consequences of high oil prices to much of the world economy during the 1970s, and the unanticipated fall in commodity prices that would later make debt repayment difficult.
Reaction to the legacy of the debt crisis and slow growth during the 1980s led to a wave of privatizations in the 1990s. Many Latin American governments privatized state-owned enterprises, such as electricity and telecommunications, and opened up trade restrictions. Similar changes occurred outside Latin America, from Britain and the U.S. (during the Margaret Thatcher/Ronald Reagan years) to Russia and China's accelerating economic liberalization during the 1990s to speed economic growth and employment.
Often the neoliberal reforms brought the seeds of crisis; for example, in the Argentinian Corralito crisis, the government was forced to withdraw after three days of popular riots. In Mexico, tortilla price increases sparked protests and demands for price controls, which the leadership handled with a Tortilla Price Stabilization Pact capping prices for a fixed time period.
The economic debate continued as reforms to weak and closed Latin American economies led to external shocks and competition such as through privatization and the North American Free Trade Agreement (NAFTA) in Mexico and other trade agreements and privatizations throughout Latin America. While orthodox economics point to longer term gains for quickly modernizing countries like Chile, slower moving countries have considered retracting from the initial shocks. Some blamed a "neo-liberal" economic model favored by an unpopular US government. The "neo-liberal" tag, along with the label of the "Washington Consensus" have been used to criticize harsh economic policies on the one hand, and on the other hand some demonized orthodox economic science and policies by tying them directly to the unpopular U.S. government which faced widespread distrust in Latin America. Throughout the world, orthodox economists generally agree that the older socialist policies favored by many populists have hindered Latin American economies and that today further neo-liberal economic reforms would be needed to compete in the international arena for more jobs and faster growth. Support for Latin American socialism continues within economic circles of both Latin America itself and elsewhere, that rely on pro-socialist works such as "Whither Socialism?" by Joseph Stiglitz..
The US has intervened in Latin American governments on many occasions where populism has threatened its interests: the interventions in Guatemala, when the populist Arbenz government was overthrown by a coup backed by the American company United Fruit and the American ambassador in 1954, and Augusto Pinochet's Chilean coup in 1973 are just two cases of American intervention. Daniel Ortega's Sandinista government in Nicaragua was also viewed as a threat to US foreign policy during the Cold War, leading the United States to place an embargo on trade with the Sandinista's Soviet-sponsored regime in 1985 as well as supporting anti-Sandinista rebels. Another example of US intervention has been seen in Colombia, particularly since the assassination of the populist leader Jorge Eliecer Gaitan in April 1948. Gaitan supported land reform and other socialist initiatives which posed a threat to American interests; it is for this reason that Gaitan's assassination is alleged to have been a CIA plot. To this day Colombia continues to be the US's most important ally in the region with continuous military aid under Plan Colombia.
Populism has remained a significant force in Latin America. Populism has recently been reappearing on the left with promises of far-reaching socialist changes as seen in Venezuela under Hugo Chavez. These socialist changes have included policies nationalizing energy resources such as oil to enable a socialist transformation. The Venezuelan government often spars verbally with the United States and accuses it of attempting to overthrow Chavez after supporting a failed coup against him. Chavez has been one of the most outspoken and blunt critics of U.S. foreign policy. Nevertheless, a large commodity trade continues between Venezuela and the U.S. due to the economic constraints of oil delivery and the proximity of the two countries.
In the 21st century, the large numbers of voters living in extreme poverty in Latin America has remained a bastion of support for new populist candidates. By early 2008 governments with varying forms of populism and with some form of left leaning social democratic or democratic socialist platform had come to dominate virtually all Latin American nations with the exceptions of Colombia, El Salvador and Mexico. This political shift includes both more developed nations such as Brazil with its ruling Workers' Party, Argentina's Front for Victory and Chile with its Socialist Party, and smaller income countries like Bolívia with its Movement towards Socialism and Paraguay with the Patriotic Alliance for Change. Populist candidates have been defeated in middle-income countries such as Mexico, in part by comparing them to Venezuela's controversial Hugo Chavez, whose socialist policies have been used to scare the middle class. Nevertheless, populist candidates have been more successful in poorer Latin American countries such as Bolivia (under Morales), Ecuador (under Correa) and Nicaragua (under Ortega). By the use of broad grassroots movements populist groups have managed to gain power from better organized, funded and entrenched groups such as the Bolivian Nationalist Democratic Action and the Paraguayan Colorado Party. 
Countries in Latin America with high rates of poverty, whose governments maintain and support unpopular privatizations and more orthodox economic policies which don't deliver general gains through society, will be under pressure from populist politicians and movements accusing them of benefiting the upper and upper-middle classes and of being allied to foreign and business interests.
In Mexico, Andres Manuel Lopez Obrador's candidacy sparked very emotional debates throughout the country regarding policies that affect ideology, class, equality, wealth, and society. Andres Manuel Lopez Obrador's most controversial economic policies included his promise to expand monthly stipends to the poor and elderly from Mexico City to the rest of the country and to re-negotiate the North American Free Trade Agreement to protect the Mexican poor.
The ruling party in Mexico, the National Action Party (PAN), portrayed him as a danger to Mexico's hard-earned economic stability. In criticizing his redistributive promises that would create new entitlement programs somewhat similar to social security in the US (though not as broad in scope) and his trade policies that would not fully uphold prior agreements (such as NAFTA), the economic debate between capitalists and socialists became a major part of the debate. Felipe Calderon, the PAN candidate, portrayed himself as not just a standard-bearer for recent economic policy, but as a more proactive candidate, to distance himself from the main criticisms of his predecessor Vicente Fox regarding inaction. He labeled himself the "jobs president" and promised greater national wealth for all through steady future growth, fiscal prudence, international trade, and balanced government spending.
During the immediate aftermath of the tight elections in which the country's electoral court was hearing challenges to the vote tally that had Calderon winning, Obrador showed the considerable influence over the masses that are a trademark of populist politicians. He effectively led huge demonstrations, filling the central plaza with masses of sympathizers who supported his challenge. The demonstrations lasted for several months and eventually dissipated after the electoral court did not find sufficient cause from the challenges presented to overturn the results.
There have been several versions of a populist party in the United States, some inspired by the Populist Party of the 1890s. This was the party of the early U.S. populist movement in which millions of farmers and other working people successfully enacted their anti-trust agenda.
Other early populist political parties in the United States included the Greenback Party, the Progressive Party of 1912 led by Theodore Roosevelt, the Progressive Party of 1924 led by Robert M. La Follette, Sr., and the Share Our Wealth movement of Huey Long in 1933–35.
George Wallace, Four-Term Governor of Alabama, led a populist movement that carried five states and won 13.5% of the popular vote in the 1968 presidential election. Campaigning against intellectuals and liberal reformers, Wallace gained a large share of the white working class vote in Democratic primaries in 1972.
Populism continues to be a force in modern U.S. politics, especially in the 1992 and 1996 third-party presidential campaigns of billionaire Ross Perot. The 1996, 2000, 2004, and the 2008 presidential campaigns of Ralph Nader had a strong populist cast. The 2004 campaigns of Dennis Kucinich and Al Sharpton also had populist elements. The 2004 and 2008 Democratic presidential candidate John Edwards has been described by many (and by himself) as a "one economic community, one commonwealth" populist.
Comparison between earlier surges of populism and those of today are complicated by shifts in what are thought to be the interests of the common people. Jonah Goldberg and others argue that in modern society, fractured as it is into myriad interest groups and niches, any attempt to define the interests of the "average person" will be so general as to be useless.
In 1984, the Populist Party name was revived by Willis Carto, and was used in 1988 as a vehicle for the presidential campaign of former Ku Klux Klan leader, and later member of both the Republican Party and the Democratic Party, David Duke. Right-wing Patriot movement organizer Bo Gritz was briefly Duke's running mate. This incarnation of populism was widely regarded as a vehicle for white supremacist recruitment. In this instance, populism was maligned by the use of a definition of "the people" which was not the prevailing definition.
Another populist mechanism was the initiative and referendum driven term limits movement of the early 1990s. In every state where term limits were on the ballot, the measure to limit incumbency in Congress passed. The average vote was 67% in favor. However, the U.S. Supreme Court struck down term limits in 1995 in the court case U.S. Term Limits, Inc. v. Thornton.
In 1995, the Reform Party of the United States of America (RPUSA) was organized after the populist presidential campaign of Ross Perot in 1992. In the year 2000, an intense fight for the presidential nomination made Patrick J. Buchanan the RPUSA standard bearer. As result of his nomination as party candidate there were many party splits, not only from Buchanan supporters after he left the party, but also moderates, progressivists and libertarians around Jesse Ventura who refused to collaborate with the Buchanan candidacy. Since then the party's fortunes have markedly declined.
In the 2000s, new populist parties were formed in America. One was the Populist Party of America in 2002; another was the Populist Party of Maryland formed to support Ralph Nader in 2004, which ran candidates for governor, lieutenant governor, U.S. Senate and state delegate in the 2006 elections. Other examples are the American Populist Party, founded in 2009, and the American Populist Renaissance, founded in 2005. The American Moderation Party, also formed in 2005, adopted several populist ideals, chief among them working against multinational neo-corporatism.
Some think-tanks such as the Cato Institute in America or the CEE Council in Europe have argued that the increasingly populist polarization of both Congress and the US body politic at large could hinder the Obama administration’s plans to reform health care and revamp bank regulations
Friedrich Ludwig Jahn, a Lutheran Minister, a professor at the University of Berlin and the "father of gymnastics," introduced the concept of Volkstum, a racial nation that draws on the essence of a people that was lost in the Industrial Revolution. Adam Mueller went a step further by positing the state as a bigger totality than the government institution. This paternalistic vision of aristocracy concerned with social orders had a dark side in that the opposite force of modernity was represented by the Jews, who were said to be eating away at the state. Populism also played a role in mobilizing middle class support for the Nazi Party in Weimar Germany.. In this case, distressed middle–class populists during the pre-Nazi Weimar period mobilized their anger at government and big business. According to Fritzsche:
The Nazis expressed the populist yearnings of middle–class constituents and at the same time advocated a strong and resolutely anti-Marxist mobilization.... Against “unnaturally” divisive parties and querulous organized interest groups, National Socialists cast themselves as representatives of the commonwealth, of an allegedly betrayed and neglected German public....[b]reaking social barriers of status and caste, and celebrating at least rhetorically the populist ideal of the people’s community...
In the late 18th century, the French Revolution, though led by wealthy intellectuals, could also be described as a manifestation of populist sentiment against the elitist excesses and privileges of the Ancien Régime.
In France, the populist and nationalist picture was more mystical, metaphysical and literarian in nature. Historian Jules Michelet (sometimes called a populist) fused nationalism and populism by positing the people as a mystical unity who are the driving force of history in which the divinity finds its purpose. Michelet viewed history as a representation of the struggle between spirit and matter; he claims France has a special place because the French became a people through equality, liberty, and fraternity. Because of this, he believed, the French people can never be wrong. Michelet's ideas are not socialism or rational politics, and his populism always minimizes, or even masks, social class differences.
In the 1950s, Pierre Poujade was the leader of the right-wing populist movement Union de Defense Commercants et Artisans (UDCA). Jean Marie Le Pen (who was UDCA's youngest deputy in the 1950s) can be characterized as right-wing populist or extreme-right populist.