As a one-term president who remains constitutionally eligible to be elected to a second term and who became the presumptive Republican nominee for president in March 2024, Trump has an evolving legacy. Assessments of the range of his impacts will surely change in the years to come. Nonetheless, his effect and legacy on the institution of the presidency, the Republican Party, and key aspects of democratic governance in the United States are already evident.

Through his campaigns, presidency, and post-presidency, including his lies about the 2020 election results, Trump exercised particular influence over the shape and operation of the Republican Party. In the late 20th and early 21st centuries, the Republican Party expanded its state and federal gains in elections and broadened its appeal. As it did so, important ideological rifts emerged within the party. One wing of the party focused more on big business and global trade, and favored an aggressive, often belligerent, foreign policy. The other focused on cultural and social issues, often with a populist bent that criticized powerful elites, whether in the government, media, or corporate sectors. Previous Republican presidents and party leaders tried, with varying degrees of success, to cater to both camps.

Trump’s aggressive and racist approach to immigration, his disengagement from foreign alliances, his tendency to praise autocrats and dismiss liberal democratic foreign leaders, and his refusal to disavow white supremacist groups marked a profound break from the past. Although he favored certain “traditional” Republican Party positions—including the Tax Cuts and Jobs Act of 2017—and appointed socially conservative justices from the same list that any Republican president would have used, his rhetoric and priorities shifted the Republican Party decidedly.

His upset win against Hillary Clinton in 2016, despite losing the popular vote, convinced many Republicans that the only path to electoral success lay in appealing to Trump’s base of voters. As a result, many commentators observed that, even in the years after Trump left office, the Republican Party had become “the Party of Trump”: candidates sought his endorsement and approval, believing that they would be more successful if they embraced his positions, from a hardline on immigration to denying the results of the 2020 election. Moderate Republicans, particularly those who criticized Trump, lost influence within the party, and many lost elections.

Trump’s presidency also shined a light on an aspect of the American presidency and the operations of democratic governance that had frequently been overlooked in public life: the importance of political and social norms and the degree to which the system depended on a mutual respect for them. Although many laws govern the behavior of elected officials, many of the practices Americans had come to expect from their leaders were not codified in law but rather in tradition—what social scientists call norms. Trump, who prided himself on his independence and unique approach to politics, routinely violated political norms.

He refused, for example, to divulge personal financial information about himself or his company. Although every president since Gerald Ford had released prior years’ tax returns, Trump claimed that he could not do so because his taxes were under audit. (The IRS denied that Trump was barred from releasing his tax returns.) Similarly, past presidents with significant financial or business interests had put their assets in blind trusts to avoid any appearance that their presidential decisions would be influenced by their personal interests. Although Trump named his adult sons as the heads of the Trump Organization, he created no legal separation between himself and the operations of his business.

In addition, past presidents recognized the importance of demonstrating transparency when questions about presidential conduct arose and agreed to appoint investigators and special prosecutors, even when they themselves were the subject of the investigation. Trump fired FBI Director James Comey, which was his legal right to do, but he did so to impede an investigation of the 2016 election. During Robert Mueller’s investigation, Trump refused to cooperate, discredited the process, and asked his counsel to fire Mueller (he refused). And throughout his presidency, Trump routinely attacked his former campaign rival Hillary Clinton, even asking law enforcement to investigate her, breaking the long-established norm of winning graciously and affirming the patriotism and good will of one’s political opponents. In so doing, he furthered the country’s partisan polarization and the tendency for people on one side to see those on the other as alien, evil, and un-American.

By far the most significant norm that Trump violated was respect for the peaceful transition of power. By refusing to publicly accept what he knew, and was told repeatedly, about his loss to Joe Biden in 2020, Trump perpetuated a lie that enflamed passions and resulted in a violent insurrection on January 6, 2021. He not only encouraged crowds of armed people to break into the US Capitol to interrupt the certification of election results but also, despite pleas from lawmakers and his advisors, refused to intervene for several hours while the violence unfolded. In refusing to attend Joe Biden’s inauguration and continuing to insist that the election results had been manipulated and the presidency “stolen” from him, he weakened public faith in elections and the democratic process more broadly.

As an ex-President, Trump has been unusually active in political life, even as an increasing number of investigations create legal and financial peril for him. He routinely holds rallies, both for fellow Republican politicians and for himself, and collects campaign contributions from supporters. Prior former presidents, by contrast, typically maintained a low profile, allowing their successors to establish themselves as leaders (even when they were from different parties and had different policy views). Other former presidents also typically spend time in their first few years out of office planning presidential libraries, working on memoirs, and establishing non-profit organizations. 

Trump, by contrast, remains a prominent force in public life and a candidate for president. In 2023, Trump was indicted in four separate legal cases on charges related to the January 6 insurrection, the effort to pressure officials to overturn the results of the 2020 election, the illegal handling of classified documents, and the payment of hush money during his first campaign. Despite his legal troubles, Trump won almost all the Republican primaries and became the presumptive GOP nominee for president by March 2024.