I'll vote for someone I wouldn't trust to watch my children, wouldn't invite to my dinner table, and wouldn't spend a day walking through the zoo with.
I'll vote for someone who would rub me personally the wrong way, irritate me, and generally cause me negative emotion.
I'll vote for someone who wouldn't be invited to a family cookout, trusted with my wallet, or asked to dog sit while I went out of town.
Why will I vote for that person? Because those are the options we're presented with.