In the 2010 race to replace retiring Republican Senator Kit Bond in Missouri, Democratic nominee Robin Carnahan defended the Obama administration and the agenda of Nancy Pelosi and Harry Reid.  Missouri voters responded by flocking to the Republican candidate Roy Blunt, who trounced Carnahan by 14 points, 54/40.  With that in mind, the Democratic incumbent for Missouri in the 2012 Senate race, Claire McCaskill, might be forgiven if she decided to put a little distance between herself and Barack Obama in a state whose voters have apparently been shown enough of Hopenchange.

If she does, though, Democratic Congressman Emanuel Cleaver warned McCaskill this weekend that it would be “an act of disloyalty”:

Rep. Emanuel Cleaver (D-Mo.) warned Sen. Claire McCaskill (D-Mo.) of “disloyalty” to President Obama if she should seek to distance herself from the White House in her re-election campaign.

Cleaver, who’s seen as the likely next leader of the Congressional Black Caucus (CBC), cautioned the centrist senator of distancing herself from Obama, the way many endangered incumbents had done in the closing weeks of the 2012 election.

“Any attempt to extricate herself from him will be an act of disloyalty,” Cleavertold McClatchy in a piece profiling McCaskill’s re-election campaign. “She will not do that at all.”

She may not have the ability to do that.  McCaskill voted for the entire Obama agenda in the 111th Session of Congress, including ObamaCare, Porkulus, and the Wall Street reform package.  McCaskill has two years in which to “distance” herself from Obama on whatever is left of the Democratic agenda, which will still prevail in the Senate, but apart from backing a new push for cap-and-trade, she’d be hard pressed to show any daylight at all.

But if she could, wouldn’t that be better for Democrats?  After all, regardless of her rhetoric, McCaskill has proven a very reliable vote in the upper chamber for the President.   The Hill’s suggestion that she has demonstrated some sort of maverickiness by backing earmark reform and spending caps hardly put her at odds with the White House, which regularly pays lip service to both ideas while doing nothing at all to abide by them.

Cleaver’s warning sounds as though he’s considering a primary challenge to McCaskill’s left in 2012, or at least putting it on the table to ensure her “loyalty” to the party line.  That should sound like sweet music to Republicans, who are likely to take the seat away in two years in any case, and much more likely if McCaskill gets pushed into Carnahan’s strategy.