I mean, I can admire Bill Clinton's ability to build a solid base and Carter's commitment to his personal convictions. Heck, even Obama can deliver his message on point. Doesn't mean that I think any of them are great leaders, but they do have some positive characteristics, even though those characteristics are misapplied.
That reminds me of the joke about the woman who always found good in people. Someone told her "You could find something nice to say about the devil!" She said "Well, he is a hard worker."
I probably botched it, but you get the idea. You are correct about almost all people having at least one good trait.