Then, who exactly do you imagine will?
You can vote FOR Obama, you can vote FOR Romney, or you can vote FOR weakening whichever bastard wins.
There is no such thing as voting "against," no matter what you want to believe. It is materially impossible for you or for me to vote "against" Obama or Romney. If you vote for Romney, you mean it to be a vote "against" Obama, but you will be badly mistaken, and rudely surprised if Romney wins, especially if he wins in a landslide. You would RUE THE DAY you realized that Romney twisted your anti-Obama vote into a pro-Romney mandate.
Obama is very weak in the polls, so a third party vote is hardly "handint it to Obama." On the contrary, a third party vote will help prevent just as big a disaster -- statist authoritarian Romney winning in a landslide. You had BETTER PONDER THE CONSEQUENCES of a Romney win and STOP obsessing over Obama.
If conservatives and Americans sick of government vote the way their common sense tells them -- that is, that both Obama and Romney are bad for America -- they will vote third party and if one in three Americans do that, then whichever guys wins will only have about one third of the popular vote, which will make him weak in office. That is what I will be voting FOR. If Romney wins, that would be bad; if Obama wins in a scenario where nearly two in three Americans rejected him at the ballot box, he would be a mockery. HE IS A SCARECROW. Grow a pair, please.
You, on the other hand, will be voting to make the Republican party turn hard left.