Trump and Hillary avi's can get a bit annoying, but I don't really mind them, if that's what they want to do, that's fine I guess, but I'm just going to put it out there that making your policital support public like that may not be the best idea, and might make a few enimies sadly. You know how messy this election is.
I'll probably never do it, but if at any point, my avi becomes Jill Stein, it's only because sadly most people probably don't even realize that she's in the race, and she deserves more publicity. Hillary and Trump don't need that, everyone already knows who they are, and have already formed opinions on them. Your avi isn't going to change any votes.
I don't mind them to be honest. Avis are just meant to help represent your personality or interests (unless your avi is meant to be ironic/satirical), and if you feel like a political candidate fits that description, go for it