Congress' most unapologetic fan of big-money politics is backing a ban on pork-barrel earmarks and avoiding an early battle with conservatives in his own party who had threatened to force a vote on the matter.

But the switch by Kentucky Sen. Mitch McConnell may not have averted an effort to put senators on the record for or against earmarks. Missouri Democrat Claire McCaskill, long an opponent of earmarks, said Tuesday she would join Sen. Tom Coburn, R-Okla., in trying to force a vote on extending the ban on the practice through 2013.

Such a vote would put senators of both parties on the spot. Asked whether she was concerned that Democrats would look out-of-touch if they tried to stand in the way, McCaskill replied, "Yes."

"I'm glad that Republican leadership is coming around to this idea," she said. "Now, it's my Democratic colleagues turn to get on board."

It was unclear whether they would.

The debate over earmarks, intensified by the midterm campaign season, gripped Congress virtually from the moment lawmakers returned this week to finish left-over business.

In his first remarks of the lame-duck session, McConnell long a defender of designating money for home-state projects, said he was heeding the message sent by voters so distrustful of government that they swept Democrats from power in the House. McConnell said the abuse of the earmarking system turned it into a symbol of government waste that Republicans do oppose.

"Old habits aren't easy to break," McConnell, the Senate minority leader, noted.

But he and other earmark proponents were under pressure to acknowledge the tea party-fueled public anger over government spending and "back-room deals" in Congress.

Just hours before McConnell spoke, Sen. Jim DeMint, R-S.C., promoted the ban on remarks to tea party activists at a Capitol rally, saying he was forcing a vote to see whether entrenched Senate veterans have "gotten the message."

On Tuesday, he complimented McConnell for changing his position, telling CBS's "The Early Show" that he's pleased McConnell listened not only to other GOP lawmakers but also to the voters.

DeMint called it a "culture change," which he said has long been overdue in Washington.

House Republicans already are moving to extend their moratorium on earmarks, and President Barack Obama has said he supports a crackdown on the practice.

"We can't stop with earmarks as they represent only part of the problem," Obama said in a statement. "I look forward to working with Democrats and Republicans to not only end earmark spending, but to find other ways to bring down our deficits for our children."

Earmarking is the longtime Washington practice in which lawmakers insert money for home-state projects like road and bridge work into spending bills. Critics say that peppering most spending bills with hundreds or even thousands of such projects creates a go-along-get-along mindset that ensures that Washington spending goes unchecked.

McConnell, a 26-year veteran of the Senate and longtime member of the Appropriations Committee, had argued in the past that banning earmarks would shift too much power to Obama and wouldn't save taxpayers any money.

"I know the good that has come from the projects I have helped support throughout my state. I don't apologize for them," he said.

McConnell's move also forestalls a possible fight with the House, where Speaker-to-be John Boehner, R-Ohio, poised to become the most powerful Republican in Washington, had put people on notice that there won't be any earmarks in spending bills.

The developments took Senate Democrats, who remain the majority party in the chamber, by surprise, and top Democrats said they stand by the practice. A spokesman for Majority Leader Harry Reid, freshly re-elected after a campaign in which he boasted of his ability to bring home the bacon to Nevada, said Reid believes it's up to each senator to decide whether he or she will seek earmarks.

"From delivering $100 million in military projects for Nevada to funding education and public transportation projects in the state, Sen. Reid makes no apologies for delivering for the people of Nevada," Reid spokesman Jim Manley said. "He will always fight to ensure the state's needs are met."