You only get to do that after you understand their reasons, which you can then judge.
> and I only know how they voted because they told me
It doesn't work like that. People don't generally run around, telling everyone who they voted for. It usually comes up in conversations, where the person who divulges their choice don't expect to get hated for it.
> Also, I'd put hating people for the color of their skin, the sexuality, their religion, ... as much much stupider.
I agree with that (maybe not with the much much part, because to me it seems to be a similar kind of stupidity; different flavours of the same bug in thinking). This doesn't invalidate my point though. People should not do either of those things.
Your conversation example is basically saying that even understanding your reasons that I'm supposed to give you a pass because ... because what?
As for stupider, the color of your skin or your sexuality aren't choices. Whether you voted for Trump is. Holding someone accountable for their choices isn't stupid. Hating them for their race, sexuality, ... is.
Your equivocation isn't getting anywhere.
I'd call that holding them accountable and I only know how they voted because they told me. Also, I'd put hating people for the color of their skin, the sexuality, their religion, ... as much much stupider.