In the end it was not close. Richard Mourdock pummeled the veteran incumbent Sen. Richard Lugar (R-Ind.) by more than 20 points.

At first blush this might seem to be a repeat of 2010: Diligent, moderate incumbent taken out by wide-eyed Tea Party loony. But Mourdock is no Sharron Angle or Christine O’Donnell. And Lugar had gotten out of touch with his constituents and had long ago ceased to be an effective reformer or constructive player in the Senate.

Certainly, conservatives were fed up with Lugar’s penchant for giving President Obama cover (on the START debate, for example) and for rubber-stamping Obama appointees (especially judges). But this was a lesson as much about incumbentitis — the presumption that with seniority came the luxury of ignoring constituents and the determination to go along to get along — as ideology.

Moreover, Mourdock is no political novice. He is currently state treasurer and has spent time in state and local government since the 1990s. If elected it’s not clear whether he would be a recalcitrant obstructionist in the mode of Sen. Mike Lee (R-Utah) or a force for reform in the vein of Sen. Pat Toomey (R-Pa.).

It is far from clear whether Republicans have slit their own throats for the general election, as they did in Nevada and Delaware in 2010. Indiana remains a red state, one that Mitt Romney is expected to win, thereby boosting down-ticket Republicans. Moreover, Mourdock’s opponent, Rep. Joe Donnelly (D-Ind.), is vulnerable insofar as he has voted with the White House on legislation that is hardly popular back home (e.g., Obamacare, the stimulus).

The onus is now on Mourdock to show he can run a disciplined general-election campaign and, if elected, be more than a reflexive “no” vote on any imperfect legislation (i.e. every bill). If so, he’ll show that Republicans can advance their causes by dumping incumbents who have overstayed their welcome.