Glenn, linking to this article describing how Libertarians helped swing the South Dakota senate race, points out that Libertarians (and other third parties) make their impact primarily by affecting the outcomes of close elections.

Well, the solution is for the Republicans to avoid the big-government intrusiveness that alienates libertarian-leaning voters. But are they smart enough to realize that? The push on the Homeland Security bill, and Trent Lott’s comments about reopening the abortion issue, suggest that they’re not. But this is how third parties traditionally have an impact — by costing one of the two major parties close elections.

Well, yes, as a general principle. But in the case of South Dakota, you can’t just point the finger at the three thousand Libertarians. Mr. Miller missed the real story, which was that the Republicans lost many thousands more Republican votes from Republican voters who bought the Democratic line that South Dakota would have more clout with two Senators in the majority party.

Obviously, in retrospect, they screwed themselves.

While I’d prefer that Thune had won, I have trouble spooling up the tearworks for SD Republicans, who voted for crass political influence over party principle, and had no faith in their own party to win a majority. Now they’ve got two Senators in the minority, and it serves them right.