Rep. Emanuel Cleaver (D-Mo.) warned Sen. Claire McCaskillClaire Conner McCaskillConservatives spark threat of bloody GOP primaries Congress needs to work to combat the poverty, abuse and neglect issues that children face Lobbying world MORE (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,” Cleaver told McClatchy in a piece profiling McCaskill's re-election campaign. “She will not do that at all.”

McCaskill is one of the centrist Democrats who managed victory in the 2006 election thanks to the headwinds favoring her party in that cycle.

Since winning, though, there have been signs that the Show-Me State has trended Republican. Rep. Roy BluntRoy Dean BluntDemocrats detail new strategy to pressure McConnell on election security bills Democrats detail new strategy to pressure McConnell on election security bills Senate Democrats to try to force additional election security votes MORE (R) easily secured victory in the state's Senate race this fall, for instance. And McCaskill might feel justified in running from Obama in 2012, since it was one of the few swing states Sen. John McCainJohn Sidney McCainMeghan McCain clashes with Joy Behar as the 'sacrificial Republican' on 'The View' The DNC's climate problems run deep Trump's health care focus puts GOP on edge MORE (R-Ariz.) managed to hold onto the 2008 presidential election, while Obama was sweeping to victory elsewhere.

McCaskill has sided with the president and majority Democrats on a series of key votes. She voted for healthcare reform, Wall Street reform and the stimulus bill.

But on other issues, she's sought to assemble a maverick record. She led the (successful) effort to do away with the Senate's longtime practice of allowing members to place anonymous holds on presidential nominees. She has joined with Sen. Jeff SessionsJefferson (Jeff) Beauregard SessionsAlabama senator: Sessions hasn't ruled out Senate bid Alabama senator: Sessions hasn't ruled out Senate bid The Hill's Morning Report - Trump to kick off bid for second term in Florida MORE (R-Ala.) to push for legislation capping discretionary spending. And she's also long favored earmark reform, an effort to which Obama lent his support in his weekly radio address on Saturday.

“Earmark reform has been a lonely fight for a long time, so it’s encouraging to have others taking this issue seriously, especially among Democrats since I will be the only senator from my party opposing earmarks after the new year,” McCaskill said Saturday in a statement. “The bottom line is that tax dollars shouldn’t be doled out based on politics or secret deals, and it’s time both Democrats and Republicans join together to stop them.”