Do you know your views are in the minority...
Historical rankings of presidents of the United States - Wikipedia
These are
Notable scholar surveys not Fox news lemmings...
Interesting to note that these notable scholars rank Reagan and Eisenhower as top ten. Shows they are not partisan
I think you really need to know whether the Presidential Historians/Political Scientist are registered Republicans, Democrats, or Independent/Other. Political bias and partisanship will have the greatest impact on the most recent Presidents. So siting a President ranking high from decades ago is not really a way to determine if the list was skewed because of partisanship.
You should probably have 3 different list:
A. One done by 100 registered Republican Presidential Historians/Political Scientist
B. One done by 100 registered Democratic Presidential Historians/Political Scientist
C. One done by 100 registered Independents/other smaller political parties Presidential Historians/Political Scientist
You then average the results of each of the three list into one list. While not perfect, you get a list that is far more free of political bias and partisanship than the ones shown on Wikipedia.
I think if you could see the party registration status of those contributing to the list on Wikipedia, you find that most would have strong majorities of registered Democrats.