Some are down right nasty. I'm unfollowing some since I get enough news about the upcoming US election coming at me from everywhere...last place I need/want it is from is Twitter.
If you're using Twitter for business I would think spewing your political beliefs in your tweets would be bad for business if you get folks unfollowing. What's the old saying? Don't discuss politics and religion among friends. You won't be converting anyone to your side in 140 characters or less.
One thing is a tweet about an interesting article or blog post about candidate so-and-so here but a tweet saying candidate so-and-so is a [censored] [censored]...just makes those folks tweeting it look unprofessional IMHO.
One thing is for sure...I can't wait until this election is OVER!