I know what you mean, but he didn't say to go and vote for Democrats. He was talking about withholding support from the republicans by either staying home or voting for a third party.
That is not the same thing as voting for a democrat.
I happened to love my Senator (Kyl), but even as much as I detest McCain, I would have hesitated to vote against him to give the win to someone like Pederson and I have never sat out an election since I became old enough to vote. My biggest mistake ever was voting for Perot and electing Bill Clinton ergo voting 3rd party isn't any different than staying home or voting for the rat.
It effectively is. Haven't we learned yet that voting third-party gives the race to the Democrats? Just look at Montana - the Republicans would still have the Senate if it weren't for the third-party votes?