I do this, or at least I like to think I do. For example, I am firmly in favor of socialized medicine, but I understand why many people are against it (both the "they don't understand how it actually works in other countries" camp, and the "they understand it and just don't think it's a good idea" camp). I'm firmly in favor of stricter gun control (although I think the Democrats should ditch it, as it's hurting them and it's way down on the list of priorities) but I understand why people oppose it.
I was basically raised Republican, spent some time as a libertarian, and gradually came around to a Democrat-leaning independent viewpoint. I understand why someone would have voted for Mitt Romney. I understand why someone would have voted for John McCain. I seriously considered voting for John McCain, and the main reason I didn't was his choice of VP.
But Trump eludes me. The man is basically what you get when the worst kind of used car salesman is born into money. I cannot understand how anyone can look at him and say, yes, that man should be leading this country. Not because he disagrees with what I, a Democrat-leaning independent believe, but because he clearly has no actual beliefs, principles, or policies of his own, and for nearly every position he has ever espoused, he has also espoused the opposite, sometimes within the same sentence.
I can understand why a person would believe that we should have less gun control. I can't understand why that person would then vote for Donald Trump, who said that the police should search people on the street and confiscate their guns.