Trump the worst president?

A question asked by Jason Brennan at the Bleeding Heart Libertarians blog.

Trump is the worst president ever?

So say an important subset of political scientists:

That was the finding of the 2018 Presidents & Executive Politics Presidential Greatness Survey, released Monday by professors Brandon Rottinghaus of the University of Houston and Justin S. Vaughn of Boise State University. The survey results, ranking American presidents from best to worst, were based on responses from 170 current and recent members of the Presidents and Executive Politics section of the American Political Science Association.

Brennan hoped that the political scientists involved could put aside their current partisan resentment and answer this question somewhat objectively, but it appears not. Brennan writes,

Sure, I despise Trump too. But the worst president ever?

Worse than McKinley and Teddy Roosevelt, who oversaw the straightforwardly evil US-Phillipine war, which left 200,000 civilians dead? Worse than Hoover, who greatly exacerbated the Great Depression with stupid interventions? Worse than Wilson, who put Americans needlessly into the unjustifiable Great War and then so screwed up post-war negotiations that World War II became close to inevitable? Worse than the long string of presidents who oversaw the extermination, forced relocation, and genocide of Native Americans? Worse than FDR, who put Japanese Americans in concentration camps? Worse than Nixon, who had to resign because of his corruption? Worse than Bill Clinton, whose sanctions of Iraq may have killed around 500,000 Iraqi children? (Note, that this number is controversial. HT: Dan Bier) Worse than Ulysses Grant, whose administration had a cartoonish degree of corruption? Worse than Polk, who unjustly seized massive amounts of land from Mexico?

Thus we do have to ask if a more objective ranking would put Trump at the bottom. Or at least they should be a lot clearer as to the criteria used to determine "worst".