So, who will? MPR asked around and found buzz building for Hennepin County Sheriff Rich Stanek.
Another possibility: Bill Guidera, of Orono, a News Corp (Fox News) executive and Republican fundraiser.
She's going to be a tough target. One poll recently found that Klobuchar is the most popular senator on Capitol Hill, and she's earned praise as a serious legislator with a sense of humor. There's even been talk of a White House bid down the road.
Minnesota Republicans are trying to combat her reputation and popularity with a website and PR campaign painting her as a wild-eyed radical.
Could relatively unknown county sheriff Stanek beat Klobuchar? We noted a few years back, when he first ran for sheriff, that Stanek was running away from a controversial history when it comes to race. But who knows. Since then, the Strib called him "one of the savviest and most driven men ever to wear the Hennepin sheriff's uniform." Let's put it this way: Two major GOP brands in Minnesota, Michele Bachmann and Tim Pawlenty, trailed Klobuchar badly in a recent Public Policy Polling survey.
UPDATE: Forget it, Stanek tells MPR. Klobuchar's a friend:
"I'm not interested in running in 2012," Stanek said. "I'm focused on being sheriff over the next four years."
UPDATE: The buzz about the Klobuchar race prompted Eric Ostermeier at the Humphrey Institute to remind everyone that there's plenty of time yet for her challenger to emerge.
There are 642 days until Election Day, and recent Minnesota history suggests it could take a while longer for official candidacies to be announced. Senator Klobuchar herself did not announce her candidacy until April 18, 2005--some 568 days before the 2006 election.