In a column in today's NY Times (subscription required), John Tierney, reporting on Reason's libertarian shindig in Amsterdam, warns that a libertarian defection could harm Republicans this November:

The G.O.P. used to have a sizable libertarian bloc, but I couldn’t see any sign of it at the conference. (South Park creators) Stone and Parker said they were rooting for Hillary Clinton in 2008 simply because it would be weird to have her as president. The prevailing sentiment among the rest of the libertarians was that the best outcome this November would be a Democratic majority in the House, because then at least there’d be gridlock.

“We’re the long-suffering, battered spouse in a dysfunctional political marriage of convenience,” said Nick Gillespie, the editor in chief of Reason. “Most of the libertarians I know have given up on the G.O.P. The odds that we’ll stick around for the midterm election are about as good as the odds that Rick Santorum will join the Village People.”

Andrew Sullivan, the blogger who coined “South Park Republican,” was at the conference with a preview of “The Conservative Soul,” his new book on the spiritual corruption of Republicans. He said he now prefers to call himself a South Park conservative, not Republican.

“The Republicans have got to be punished for destroying conservatism,” he said, explaining why he’s rooting against the party this November. “If it requires an idiotic Democratic House to stop these people from doing what they’re doing, then good.”

I have a hard time believing that if Republicans lose this November, it will be because libertarians stay home. Don't get me wrong, the free-spending ways of Republicans will definitely hamper turnout among conservatives, but I think that most self-described libertarians had already left the Republican Party by 2004, either because of government spending, social issues, or the War on Terror. 

When asked who he would vote for in back in 2004 for this Reason survey, Gillespie said, "Probably no one but maybe Badnarik (the Libertarian Party candidate), if only to register dissent from the Crest and Colgate parties." In fact, most everybody quoted in that informal poll of libertarian-ish people either said they would vote Libertarian, vote for Kerry, or stay home. Sullivan, who can't vote because he is not a U.S. citizen, vocally endorsed Kerry the last election. So, before I'm convinced that a libertarian exodus is going to hurt Republicans, I'd need to see more evidence of libertarians who still supported Republicans in 2004 now saying that they've changed their minds.