More acutely, this survey has seen a pronounced partisan dynamic emerge, arguably in response to the Trump presidency and the Trumpification of presidential politics.
Proponents of the Biden presidency have strong arguments in their arsenal, but his high placement within the top 15 suggests a powerful anti-Trump factor at work. So far, Biden’s record does not include the military victories or institutional expansion that have typically driven higher rankings, and a family scandal such as the one involving his son Hunter normally diminishes a president’s ranking....
Academics do lean left, but that hasn’t changed since our previous surveys. What these results suggest is not just an added emphasis on a president’s political affiliation, but also the emergence of a president’s fealty to political and institutional norms as a criterion for what makes a president “great” to the scholars who study them.
https://www.latimes.com/opinion/story/2024-02-18/trump-biden-presidents-day-ranking-poll-election-2024
Even the two authors of this survey, Rottinghaus and Vaughn, admit the left biases of their "experts". Historians and political scientists always seem to trend far left, as evidenced by such assessments of the presidents.
What you see in such rankings is called "presentism", which is the interpretation of history through the lens of today's biases and political/social fads.
As an example, anyone that knows the historical details would never put a dictatorial leader like Lincoln in first place. And these "experts" have Truman in 6th place!
