Say hello to the democrats with your vote. All the things you don't like about the republicans will be 10 fold worse with democrats, but you are so smart that you outsmarted yourself with your vote. Lot's of people did the same thing when they voted for Ross Perot, and we got the democrat Clinton.
It wouldn't have happened if we had the instant runoff ballot in place. But that would be dangerous to our beloved 2-party system; if people could actually vote for the 3rd party candidate without throwing their vote away, he might eventually even win!
Had the Republicans not have gotten Clinton they would not have taken control of both houses of congress either...