For those who react to not voting for A, because B is worse in some way, there is an alternative: vote 3rd party. Any party, it doesn't matter. You're voting for a message, not a result.
The main thing is that you're entering a vote that isn't being counted in the Dem or Rep column.
If you don't vote then it doesn't count against the Dems or Reps at all.
Vote whichever 3rd party is easiest on your conscience, and you'll be voting against both parties that can't responsibly work together at the moment.