Missouri Senate candidate Robin Carnahan (D) is just the latest Democrat facing a tough race in 2010 to buck her party's leaders in Washington. 

Carnahan, who is battling Rep. Roy Blunt (R-Mo.) for the seat left open by retiring Sen. Kit Bond (R-Mo.), told voters while campaigning at the Missouri state fair Thursday, "Now is not the time to be doing anything to raise taxes."

In an interview with The Associated Press, Carnahan admitted that her position marks a shift from earlier this year.

In a February radio interview, Carnahan had said she favored extending tax cuts for the middle-class but not for the wealthiest Americans. She said then that the nation couldn't afford it.

Carnahan said in an interview Thursday with The Associated Press that her position has evolved because of an additional six months of difficult economic times, which she blamed on policies backed by Blunt.

Carnahan said she supports making permanent the tax cuts affecting lower and middle-income people and extending tax cuts for wealthier people until the economy improves enough to consider ways of balancing the budget. She declined to specify how long that extension should last. 

The issue has become a sticky one for both parties, as a handful of Democrats have come out in favor of an across-the-board extension of the tax cuts passed by Congress under former President George W. Bush. 

Most Democrats, including President Obama, only want to extend those cuts for people earning less than $200,000 a year. 

Republicans, meanwhile, have been pressed on how they square their support for extending the cuts with their calls to cut spending and reduce the federal deficit. The cuts are set to expire at the end of the year.