That's the point that I have repeatedly tried to make. If you promise your vote to a politician *no matter what*, then what do you expect from him? Would you let your spouse cheat on you once a week because you don't want to be single? Certainly not! Well, actually some of these people probably would.
My God, at least you'd think that they would be smart enough to threaten to withhold the vote if they aren't pleased with the current coarse and don't want it to get any worse. If you ain't complaining, the pols keep doing what they've been doing. You gotta let them know that you aren't happy. And never let them know that you're scared of the alternative. Show your anger, but never show the fear. The fear only plays into their hands.
That is, if they really don't like the leftward shift. Sometimes I wonder.