Indiana Sen. Richard Lugar (R) sure looks like a sucker for primary punishment - at least insofar as inviting a tough fight for renomination.
On Tuesday, Lugar was one of just eight Republicans who voted to oppose the earmark ban that his party leadership supported, a move that comes days after being the only Republican senator to publicly back Pres. Obama on his signature nuclear treaty with Russia. Of the Republican senators who split with their leadership, he's the only one facing a competitive re-election in 2012 - thanks to newfound Tea Party interest in challenging him in a primary.
Lugar's other moderate/establishment Republican colleagues facing the prospect of a primary challenge in 2012 all have become born-again earmark opponents. Sen. Kay Bailey Hutchison (R-Texas), who has defended earmarking in the past, supported the ban on the practice. Sen. Olympia Snowe (R-Maine), one of the most moderate members of the Senate but anticipating a primary challenge, stamped her newfound public opposition to earmarks by voting for the ban.
Even retiring Democratic Sen. Evan Bayh (D-Ind.), Lugar's in-state colleague, voted for the ban - in line with the sentiment of his Republican-leaning state.
But not Lugar, who declared he's running for a seventh term earlier this month. Already state Treasurer Richard Mourdock, a Tea Party favorite, has said that "the door is open" for a potential run against Lugar. Mourdock won the most votes of any statewide candidate in this year's elections. State Sen. Mike Delph (R) is another conservative candidate not ruling out a primary challenge.
Needless to say, Lugar, who didn't even face Democratic opposition last time he was on the ballot, is bound to be in for the fight of his career this time around. And that has Democrats licking their chops, giving them the opportunity to pick up a seat that would otherwise be writing off.