There is no single factual answer to “who was the worst president of the United States”; it is a judgment call that depends on the criteria you care about (war, economy, democracy, corruption, etc.). Still, historians and commentators do tend to circle around a small set of “bottom-tier” names, and more recent polls often place Donald Trump and James Buchanan at or near the very bottom, for different reasons.

Key idea: “Worst” depends on criteria

When people rank “worst presidents,” they usually look at things like:

  • Damage to democracy or institutions
  • Contribution to major national crises (like Civil War or economic collapse)
  • Corruption and scandal
  • Competence in basic governing and crisis management
  • Long‑term harm (for example, to civil rights)

Using those lenses, several presidents keep appearing in the bottom group.

Names that come up most

  • James Buchanan (1857–1861) – Often ranked worst in older scholarly surveys because he did almost nothing as the country slid toward Civil War; he believed secession was illegal but also claimed the federal government had no right to stop it, and seven states left the Union on his watch.
  • Andrew Johnson (1865–1869) – Took over after Lincoln’s assassination and actively undermined Reconstruction, opposed rights for freed Black Americans, tolerated “Black Codes,” and was nearly removed from office.
  • Warren G. Harding (1921–1923) – Personally affable but widely criticized for a weak grasp of policy, and his administration was riddled with scandals like Teapot Dome, which badly hurt public trust in government.
  • Herbert Hoover (1929–1933) – Not evil or corrupt, but judged harshly for a slow and inadequate response to the Great Depression, which deepened suffering and unemployment.
  • Donald Trump (2017–2021, and again from 2025) – In several recent expert polls and commentary pieces, Trump is ranked last for deep polarization, refusal to accept the 2020 result, the events around January 6, and a chaotic governing style; some lists explicitly label him the “worst” because of perceived damage to democratic norms and the rule of law.

Simple comparison table (common “bottom” picks)

[7][10][3] [5][10][3][7] [10][3] [3][10] [1][8][7][10][3]
President Era Why many rank them near the bottom
James Buchanan Pre–Civil War Failed to act as Southern states seceded, seen as enabling the path to Civil War.
Andrew Johnson Post–Civil War Undermined Reconstruction and civil rights for freed slaves, lenient to ex‑Confederates.
Warren G. Harding 1920s Presided over major corruption scandals, weak leadership, damaged trust in government.
Herbert Hoover Great Depression Viewed as failing to respond effectively to the economic collapse of 1929–33.
Donald Trump 21st century Recent expert rankings put him last for institutional strain, polarization, and election denial.

How historians and forums talk about it

  • Modern scholarly polls : Recent academic surveys of historians and political scientists have increasingly placed Donald Trump at the very bottom, even below the traditional “worst” (Buchanan and Andrew Johnson), mainly because of threats to democratic norms and the events surrounding the 2020 election and January 6.
  • Traditional rankings (pre‑Trump): Buchanan and Andrew Johnson usually fought over last place because one presided over the disintegration of the Union, and the other squandered the chance to build a more equal post‑war America.
  • Popular articles and forums : Many “Top 10 worst presidents” lists online mix those historical figures with more recent ones based on partisan feelings (for example, George W. Bush for Iraq and the 2008 crisis, or Trump and Biden depending on the site’s politics).

You can think of it this way:

  • If your main yardstick is “who let the country fall apart,” Buchanan is a strong candidate.
  • If your main yardstick is “who did the most lasting damage to civil rights after the Civil War,” Andrew Johnson often looks worst.
  • If your yardstick is “who most directly attacked democratic norms in modern times,” many recent experts point to Trump.

A short, neutral takeaway

Because “worst president” is fundamentally a value judgment, there is no neutral, official answer. The fairest way to phrase it is that James Buchanan, Andrew Johnson, and Donald Trump are the three names most frequently placed at or near the bottom of expert and popular rankings, for different but very serious reasons.