Today in Indiana, Senator Richard Lugar will probably be defeated in a Republican primary by State Treasurer Richard Mourdock, three-time failed congressional candidate, and Tea Party favorite. Lugar might be the single most respected member of the Senate, a guy who has been in office for 35 years, has carved out areas of interest and expertise that don't bring with them anything in the way of contributions or votes (foreign affairs, nuclear proliferation), and finds areas where he can work with Democrats. And that, of course, was his undoing. Perhaps Lugar's greatest sin in their eyes was that he maintained a good relationship with Barack Obama (horrors!). The Tea Party may be fading, but it had enough left in its tank to knock Lugar out.
So what do we learn? Michael Tomasky argues that we shouldn't shed any tears for Lugar, since he had the chance to confront his party's extremism and chose not to; had he done so, he could have gone out with some more dignity. But he didn't try to pander to his party's extremists either, so I suppose that's something. And as Tomasky points out, Lugar may have voted with Democrats on some things like judicial nominations, but on most of the high-profile ideological battles, he was right there with his party. Yet Mourdock's campaign has essentially argued that Lugar is the kind of moderate that in truth we only see in the Democratic party.
Democratic Senate moderates like Ben Nelson and Joe Lieberman don't just vote against their party sometimes, they display a naked contempt for their party's base, and take as many opportunities as possible to loudly and proudly undermine its goals. And that's what Republican moderates like Lugar and the retiring Olympia Snowe don't do. Yes, they'll gnash their teeth some and make lots of statements about how they really hope we can come up with a bipartisan solution to the problem at hand, but in the end they'll be there for the GOP when it matters. Not so the Democratic moderates.
In Nelson's case, it can be explained by the fact that he represents Nebraska, an extremely conservative state, so he has to constantly convince voters he's really not much of a Democrat. In Lieberman's case it's obviously personal pique, resentment growing out of his primary defeat in 2006 and the way base Democrats take so many opportunities to attack him. Ever since, it seems that Lieberman's sole purpose in life has been to piss liberals off, from his endorsement of John McCain to the way he almost singlehandedly killed the public option in health care reform (which he had supported previously) for no apparent reason other than it would make liberals mad.
Both Nelson and Lieberman are retiring this year, but there are still a couple of their ilk around, Democrats who are more likely to vote with Republicans the more consequential and high-profile a piece of legislation is. For Republican moderates like Lugar, the opposite is true: the more important a bill is, the more likely they are to stick with their party. That isn't the case on every last vote, but it's true often enough to define the character of their time in office.