Donald Trump, the 45th and 47th President of the United States, has been described as nationalist and right-wing populist* Kazin, Michael. How Can Donald Trump and Bernie Sanders Both Be 'Populist'?, The_New_York_Times (March 22, 2016). Becker, Bernie. Trump's 6 populist positions, Politico (February 13, 2016). with his current views being business nationalist and ultraconservative. Trump has variously described himself as "common sense" and nationalist. Prior to 2016, he at times identified with the Democratic Party.Gillin, Joshua; "Bush says Trump was a Democrat longer than a Republican 'in the last decade'", PolitiFact (August 24, 2015). Trump's political beliefs and ideologies are described as Trumpism.

Trump consistently advocates for supply-side economics, deregulation, achieving energy independence, and prioritizing the interests of domestic industry, expanding school choice and adopting a "law and order" approach to law enforcement. He is also anti-immigrant, wanting to deter illegal and unskilled migration through stricter immigration laws and enforcement. In foreign policy, he is neo-isolationist and protectionist, preferring a unilateral military policy to counter "rogue states" and deter China, eschewing collective security while diplomatically and militarily supporting Israel, and renegotiating free trade agreements while levying import tariffs to favor domestic industry.

He has been variously accused of espousing racist and misogynist views.

Trump has personally cited Roy Cohn, Arthur Laffer, and Norman Vincent Peale as influences on his worldview. Jerome Corsi, Lee Iacocca, and Roger Stone are further purported to be influences on his politics.

Political affiliation and ideology Self-described

As a New York real estate developer and celebrity, Trump often donated to and associated with whichever party held more influence in the jurisdictions where he did business. For example, he typically aligned more with Democrats in New York City, as the city was and still is a heavily Democratic jurisdiction. He frequently donated to candidates from both parties in order to "curry favor" and gain access to the political elite. Trump initially registered as a Republican in Manhattan, New York City, in 1987; since that time, he has changed his party affiliation five times. In 1999, he changed his party affiliation to the Reform Party and had even considered running a presidential campaign in 2000 as a Reformist before ultimately withdrawing from the race due to becoming disillusioned with the party and not wanting to become associated with certain members that had differing views, such as David Duke, Pat Buchanan and Lenora Fulani, whom he referred to as a Klansman, a Neo-Nazi, and a Communist respectively. In August 2001, Trump changed his party affiliation to Democratic. In September 2009, he changed his party affiliation back to the Republican Party. In December 2011, Trump changed his party affiliation to "no party affiliation" (independent) to preserve his right to run as an independent if he was dissatisfied with the Republican nominee. In April 2012, he again returned to the Republican Party and has remained a Republican since then.

In a 2004 interview, Trump told CNN's Wolf Blitzer: "In many cases, I probably identify more as Democrat", explaining: "It just seems that the economy does better under the Democrats than the Republicans. Now, it shouldn't be that way. But if you go back, I mean it just seems that the economy does better under the Democrats...But certainly we had some very good economies under Democrats, as well as Republicans. But we've had some pretty bad disaster under the Republicans."Moody, Chris; "Trump in '04: 'I probably identify more as Democrat'", CNN (July 21, 2015). In a July 2015 interview, Trump said that he has a broad range of political positions and that "I identify with some things as a Democrat."

During his 2016 presidential campaign, Trump consistently described the state of the United States in bleak terms, referring to it as a nation in dire peril that is plagued by lawlessness, poverty, and violence, constantly under threat, and at risk of having "nothing, absolutely nothing, left".Johnson, Jenna; "Donald Trump's vision of doom and despair in America", The Washington Post (July 21, 2016).Reena Flores, "Donald Trump offers dark vision of America in GOP convention speech", CBS News (July 22, 2016). In accepting the Republican nomination for president, Trump said that "I alone can fix" the system,Jackson, David; "Donald Trump accepts GOP nomination, says 'I alone can fix' system", USA Today (July 22, 2016). and pledged that if elected, "Americanism, not globalism, will be our credo." He described himself as a "law and order" candidate and "the voice" of "the forgotten men and women".Rucker, Philip; Fahrenthold, David A.; "Donald Trump positions himself as the voice of 'the forgotten men and women'", The Washington Post (July 21, 2016). Trump's inaugural address on January 20, 2017, focused on his campaign theme of America in crisis and decline.Page, Susan; "Analysis: Trump's short, dark and defiant inaugural address" , USA Today (January 20, 2017). He pledged to end what he referred to as "American carnage", depicting the United States in a dystopian light—as a "land of abandoned factories, economic angst, rising crime"—while pledging "a new era in American politics".

Although Trump was the Republican nominee, he has signaled that the official party platform, adopted at the 2016 Republican National Convention, diverges from his own views.O'Keefe, Ed; Balz Dan; Weigel, David; "In GOP platform fight, Donald Trump is a distant presence", The Washington Post (July 11, 2016). According to a The Washington Post tally, Trump made some 282 campaign promises over the course of his 2016 campaign.Johnson, Jenna; "'I will give you everything.' Here are 282 of Donald Trump's campaign promises", The Washington Post (November 24, 2016). In February 2017, Trump stated that he was a "total nationalist" in a "true sense". In October 2018, Trump again described himself as a nationalist. During the last week of his presidential term in January 2021, Trump reportedly considered founding a new political party called the Patriot Party.

As described by others Observers and analysts often attribute Donald Trump's constant shifts to pragmatism, political expediency, and a desire for influence rather than a rigid adherence to a specific ideology or party loyalty. Trump's political positions are populist, more specifically described as right-wing populist.Kazin, Michael. How Can Donald Trump and Bernie Sanders Both Be 'Populist'?, The New York Times (March 22, 2016). Becker, Bernie. Trump's 6 populist positions, Politico (February 13, 2016). Politicians and pundits alike have referred to Trump's populism, anti-free trade, and anti-immigrant stances as "Trumpism".

Liberal economist and columnist Paul Krugman disputes that Trump is a populist, arguing that his policies favor the rich over those less well off.Krugman, Paul. Obama's War on Inequality, The New York Times (May 20, 2016): "Just for the record, while Mr. Trump is sometimes described as a 'populist,' almost every substantive policy he has announced would make the rich richer at workers' expense". Harvard Kennedy School political scientist Pippa Norris has described Trump as a "populist authoritarian" analogous to European parties such as the Swiss People's Party, Austrian Freedom Party, Swedish Democrats, and Danish People's Party. Columnist Walter Shapiro and political commentator Jonathan Chait describe Trump as authoritarian. Conservative commentator Mary Katharine Ham characterized Trump as a "casual authoritarian," saying "he is a candidate who has happily and proudly spurned the entire idea of limits on his power as an executive and doesn't have any interest in the Constitution and what it allows him to do and what [it] does not allow him to do. That is concerning for people who are interested in limited government."Transcript: Donald Trump Sweeps Nebraska and West Virginia Primaries; Bernie Sanders Wins West Virginia But Gains Little, CNN (May 11, 2016). Charles C. W. Cooke of the National Review has expressed similar views, terming Trump an "anti-constitutional authoritarian." Libertarian journalist Nick Gillespie, by contrast, calls Trump "populist rather than an authoritarian".Gillespie, Nick. Donald Trump Supporters Are Less Authoritarian Than Ted Cruz Voters, Reason (March 14, 2016): "Understanding Trump as a populist rather than an authoritarian helps explain why he can get away with sloppy, inconsistent thinking." In an article for Newsweek, political theorist Rafael Holmberg described Trump's politics as even more unsettling than populism, and as a new type of political discourse. Rich Benjamin refers to Trump and his ideology as fascist and a form of inverted totalitarianism.

Legal experts spanning the political spectrum, including many conservative and libertarian scholars, have suggested that "Trump's blustery attacks on the press, complaints about the judicial system and bold claims of presidential power collectively sketch out a constitutional worldview that shows contempt for the First Amendment, the separation of powers and the rule of law." Law professors Randy E. Barnett, Richard Epstein, and David G. Post, for example, suggest that Trump has little or no awareness of, or commitment to, the constitutional principles of separation of powers and federalism. Law professor Ilya Somin believes that Trump "poses a serious threat to the press and the First Amendment," citing Trump's proposal to expand defamation laws to make it easier to sue journalists and his remark that the owner of The Washington Post, Jeff Bezos, would "have problems" if Trump was elected president. Anthony D. Romero, the executive director of the American Civil Liberties Union, wrote in an op-ed published in The Washington Post in July 2016 that "Trump's proposed policies, if carried out, would trigger a constitutional crisis. By our reckoning, a Trump administration would violate the First, Fourth, Fifth and Eighth amendments if it tried to implement his most controversial plans."Anthony D. Romero, ACLU Director: We will defend the constitution against a President Trump, The Washington Post (July 13, 2016).

Prior to his election as president, his views on social issues were often described as centrist or moderate. Political commentator Josh Barro termed Trump a "moderate Republican," saying that except on immigration, his views are "anything but ideologically rigid, and he certainly does not equate deal making with surrender." MSNBC host Joe Scarborough said Trump is essentially more like a "centrist Democrat" on social issues.Hains, Tim. "Joe Scarborough: Donald Trump Is A Centrist Democrat On Social Issue, 'It's Not Been A Secret'", Real Clear Politics (April 22, 2016). Journalist and political analyst John Heilemann characterized Trump as liberal on social issues,With All Due Respect (TV series) (April 21, 2016). while conservative talk radio host and political commentator Rush Limbaugh said that Heilemann is seeing in Trump what he wants to see.Limbaugh, Rush. Trump Walks It Back on Bathrooms (April 25, 2016): "[P]eople make Trump into what they want him to be. So here you have these two guys Heilemann and Halperin, who are liberals, and they want to like Trump, I think." Since he became president, commentators have generally characterized his policy agenda as socially conservative.