The mid-term elections are Tuesday -- save in places where vote-by-mail is allowed, like Oregon -- and while you might think your choices are between dumb and dumber, or the Devil and the deep blue sea, if you are a citizen, you can always vote against somebody.
Choose the lesser of two evils. But if you don't vote, you don't get to bitch. At the least, later, you can say, "Well, I tried to keep the son-of-bitch out of office -- I voted for the other guy."
Exercise your franchise. One vote might make the difference, and won't you feel like an idiot if the guy or ballot measure you hated won by one vote?
Even if you lose, at least you went down swinging. Do it. It matters.