Truman liked people, I think. His win in '48, sneaking it out over Dewey, was really a result of his whirlwind campaign, one that spoke plain, right to the people. Trump may have borrowed some of that iin the last couple of weeks.
Truman was not afraid of the tough decision, popular or not. Hiroshima (which he didn't think was that tough of decision), Israel, Berlin Airlift, Marshall Plan, canning MacArthur, desegregation of military (by an EO), Korea, etc.....
Hard political nuts to crack, but he waded in, moved quickly and decisively. He acted! He wasn't particularly popular (ala Trump) but I think folks (like him or not) admired his plain talking ways.
Hillary? I'm not sure I can come up with a decent presidential comp. Well, Obama is probably the best, but that one is unfair. I'm not sure any 20th Century president was as unlikeable as Ms. Clinton, nor did any return the favor with such aplomb. My sense is that people were "in her way." That includes most staffers, secret service agents, voters and other hoi polloi.
Surprisingly, she was generally well liked by her senate colleagues and I think she generally liked them. They were "equals," of course,
While her husband was all about connecting with "the people" (no pun intended), she had no skill set for it. In some ways, I think a Hillary presidency would have been a regal one. Not as in the "Camelot" Kennedy way, but in the Queen Elizabeth II sense. There would have always been an extra-thick layer of insulation between she and the nation, and a coldness coming from her.
Maybe Hoover and Nixon are the best templates. And I don't mean that in any derogatory way. Hoover's actions to forestall the impact of The Crash were active and aggressive, for their time. But he had little ability to connect with people. Nixon's first term was one of the most revolutionary in modern history: EPA, China, SALT, Title IX, ended the draft, etc. He had no connection with the people, however.
He was a brilliant, but deeply flawed man. Hillary is not in his intellectual-political class, but she wold have lived in a White House with a gate-keeper mentality around her. I hadn't thought about it until right now, but she would have been surrounded by "All the Queen's Men (and Women)." There is a Nixon-ness to her, personally, not politically.