Cooldige, Nixon, Cleveland, John Adams.
Those four two.
You realize, do you not, that Nixon and Adams were philosophically antithetical to Coolidge and Cleveland? Two of the above wanted to decrease the size and scope of the Federal government; two of the above massively expanded it. Care to take a guess as to who did what?
Generally speaking, I find that most admirers of John Adams & Richard Nixon admire them for reasons completely unrelated to the policies that they supported. Of course, that makes posting them in a topic about the most underrated President nonsensical.
It's all conservative inconsistency and hypocrisy. They know they're supposed to support someone, someway, for some reason, but the actual reasons for that support utterly escapes them. So Nixon - who created, among other things, the Occupational Safety and Health Administration and the Environmental Protection Agency, and then escalated our interventionist exploits in Vietnam - is given the same lauds as the isolationist Coolidge, who would have gutted both, only because he was "demonized" by the dag-gummed lib-uh-rul media.
American conservatism is a hollow pretense.