Which presidents are most commonly ranked lowest and why do scholars place them there?

1. Who scholars most often rank last — the usual suspects

Multiple expert surveys and compilations put Donald Trump, James Buchanan, Andrew Johnson, Franklin Pierce and William Henry Harrison in the bottom tier; one high-profile scholar poll listed Trump at 10.9 (the lowest), with Buchanan, Johnson, Pierce and Harrison rounding out the bottom five ^{[1] [3]}. Longstanding scholarly lists—such as those aggregated on Wikipedia and Siena’s expert surveys—identify Buchanan and Andrew Johnson as perennial low-rankers, with Trump joining them in more recent polls ^{[2] [4]}.

2. Why Trump shows up at the bottom of recent expert polls

Scholars place Trump low for a mix of institutional, ethical and evaluative reasons: surveys that scored him lowest cited perceived assaults on norms and governance, poor crisis leadership in historians’ eyes, and low composite scores in multi-category rankings; one project registered him as the single worst president when first included ^{[2] [5]}. Advocacy and legal groups also amplify critiques—pointing to legal convictions and prolific false or misleading statements—which compound scholarly judgments, though commentators differ on weighting such factors versus policy outcomes ^{[6] [5]}.

3. Buchanan and Johnson: constitutional paralysis and failed stewardship

James Buchanan is repeatedly ranked near the bottom because historians blame him for inaction and mismanagement in the lead-up to the Civil War, leaving the nation polarized and unprepared to prevent secession ^[2]. Andrew Johnson is ranked poorly for his opposition to Reconstruction policies and conflict with Congress, which scholars say undermined postwar reconciliation and civil-rights progress ^{[2] [3]}. These are classic examples where judgment centers on failure to meet existential national challenges ^[3].

4. Pierce and Harrison: incompetence, corruption, and short tenures

Franklin Pierce is judged harshly for policies that exacerbated sectional tensions (notably the Kansas-Nebraska fallout in longer treatments) and for being seen as a weak leader during a volatile era; William Henry Harrison’s low ranking is often technical—he died a month into his term so had little record to evaluate, which pushes some scholars to place him low or exclude him from rankings ^{[3] [7]}. Scholars differ on whether very short tenures should count against a president or be treated separately ^[7].

5. Methodology matters — why polls disagree and move over time

Different projects use different metrics: SRI and C‑SPAN-style surveys score presidents across many leadership attributes and historical context; the Presidential Greatness Project and other pollsters vary samples and timing, so results shift as new presidents serve and as scholarly perspectives evolve ^{[8] [9]}. Partisan composition of respondents and the choice to weight scandal, institutional norms, policy outcomes or long-term impact differently produce divergent bottom lists—explaining why some compilations show Trump worst while older lists emphasize 19th‑century failures ^{[4] [10]}.

6. Alternative viewpoints and contentious judgments

Not all commentators accept the same criteria. Some conservative and populist outlets contest rankings that place recent presidents low, arguing policy accomplishments or public support should carry greater weight; others embrace moral and legal considerations as determinative ^{[11] [12]}. Academics sometimes warn that assessments made too soon after a presidency mix current politics with historical judgment—C‑SPAN deferred its 2025 survey after a former president returned to office to avoid conflating history with punditry ^[2].

7. Limitations in the record and what sources don’t say

Available sources do not mention a single universally accepted algorithm for “best” or “worst” presidents; instead, the field uses plural methodologies that privilege different attributes ^{[8] [9]}. Sources also do not provide a unanimous list that all historians endorse; where consensus exists (e.g., Lincoln at the top), the bottom ranks show more fluctuation as new evidence, norms and scholarly panels change ^{[2] [4]}.

8. What to watch going forward

Expert rankings will continue to evolve as new scholarly surveys are fielded, as long-term policy consequences emerge, and as the academic community debates how to weigh institutional norms, legal accountability and political outcomes; recent polls already demonstrate substantial movement when panels, timing or respondent composition shift ^{[1] [2]}. For readers, scrutinize the methodology and respondent makeup of any ranking before treating bottom-line lists as definitive ^{[8] [9]}.