That is not true the way I see it:
I think the Conservative thing to do is to vote for a conservative in every slot possible, to include the presidency. If a third party candidate IS conservative by his nature and his record, why wouldn't I vote for him, rather than skip or stay home?
Last election, in three weeks during the Republican primary, the Christian Right lifted Huck out of the cheap seats single-handed... because they had no pro-life candidate in the top tier. They created a top-tier candidate (would that it had been Hunter they chose).
Look at FR's contribution to the tea party... Look at the TEA Party itself... cross-pollinate with the Christian, military, and civil libertarian forums...
If huck can ride the Christian Right's coattails to the spotlight and do as well as he did, literally ANY conservative could do the same...