In its sixth presidential ranking since 1982, 157 scholars surveyed by the Siena College Research Institute ranked Trump the third worst president of all time after Andrew Johnson (who was impeached) and James Buchanan (whose presidency was followed by the Civil War).
Respondents ranked each of 44 presidents on a scale of 1 (poor) to 5 (excellent) on each of twenty presidential attributes, abilities and accomplishments. Overall rankings were computed by assigning equal weight to each of those twenty categories. Trump ranked last for integrity, intelligence and overall ability. Details here.