Richard Mourdock (left) and Sen. Dick Lugar (right).
There's no shortage of compelling primary fights this year, but I'd argue none is as interesting as the Republican U.S. Senate primary in Indiana. There's only a week to go, and it's not too late for campaign watchers who haven't been keeping an eye on the race to tune in.
At the outset, perhaps the most remarkable thing is that this primary exists at all. Lugar is arguably the Senate's most respected Republican statesman, and has traditionally been considered a GOP hero among Hoosiers. The notion of him facing a credible challenger at all seems rather outlandish.
Former Sen. John Danforth (R-Mo.) said a while back, "If Dick Lugar, having served five terms in the U.S. Senate and being the most respected person in the Senate and the leading authority on foreign policy, is seriously challenged by anybody in the Republican Party, we have gone so far overboard that we are beyond redemption."
Well, guess what. Lugar is not only facing a serious challenge from Indiana state Treasurer Richard Mourdock, there's a credible chance the incumbent senator is going to lose a week from tomorrow.
For many within the Republican Party, this one race has become a proxy for the fight for the GOP's soul. Mourdock, who says Lugar isn't nearly right-wing enough, enjoys the support of Sarah Palin, the NRA, the Club for Growth, FreedomWorks, and Herman Cain. Lugar is backed by John McCain, Mitch Daniels, Eric Cantor, and the party establishment.
It reached the point last week that Young Guns Network, a group led by two former leading Cantor aides, have begun urging Democrats and independents to support Lugar in the GOP primary, and have mailings condemning Mourdouk from the left, criticizing him for wanting to shut down the Department of Education.
That's pretty remarkable in its own right. A Cantor-affiliated Republican group is going after a Republican Senate candidate for opposing the Department of Education -- despite the fact that most of Cantor's House GOP caucus has said largely the same thing.
If Lugar wins, it's a victory for the party establishment and this will remain a safe "red" seat. If Mourdouk wins, it's a victory for the party's activist wing, and the Democratic candidate, Rep. Joe Donnelly, believes he'll have a shot in November.
Remember, the fact that there's even a primary at all suggests to some party leaders that the GOP is "beyond redemption." And yet, here we are.