WASHINGTON – With the final three lawmakers named Thursday to a 12-member “supercommittee” that’s tasked with trying to cut the federal deficit by more than $1 trillion by year’s end, the budget battle on Capitol Hill begins anew.

House Minority Leader Nancy Pelosi, D-Calif., rounded out the committee’s roster by appointing three veteran liberal Democrats: House Assistant Democratic Leader Jim Clyburn of South Carolina, Democratic Caucus Vice Chairman Xavier Becerra of California, and Rep. Chris Van Hollen of Maryland, the ranking member of the House Budget Committee.

With all the pieces in place, the question now is whether the committee’s members — six liberal Democrats and six conservative Republicans — can get along and forge consensus on $1.2 trillion in deficit reductions by Thanksgiving.

If they fail, the Budget Control Act of 2011, which President Obama signed last week, triggers automatic cuts to federal agencies and defense programs in 2013.

Several budget analysts and political experts aren’t optimistic.

In announcing her picks, Pelosi repeated her call for the committee to think big but also to protect key entitlement programs in its quest to chip away at the nation’s debt, which stands at more than $14.3 trillion.

“We must achieve a grand bargain that reduces the deficit by addressing our entire budget, while strengthening Medicare, Medicaid and Social Security,” Pelosi said.

The three lawmakers Pelosi tapped strongly echo those sentiments. Clyburn, a member of the Congressional Black Caucus, is the No. 3 Democrat in the House. Becerra is the House’s No. 5 Democrat and a member of the liberal Congressional Progressive Caucus. Van Hollen is a former chairman of the Democratic Congressional Campaign Committee.

“This is not a centrist lineup,” said Andrew Fieldhouse, a federal budget-policy analyst at the Economic Policy Institute, a liberal research center. “This represents where the Democratic Party is outside of Washington.”

In addition to Pelosi’s picks, Senate Majority Leader Harry Reid, D-Nev., earlier chose three liberal senators for the committee: Patty Murray of Washington state, John Kerry of Massachusetts, and Max Baucus of Montana.

House Speaker John Boehner, R-Ohio, on Wednesday tapped Republican Conference Chairman Jeb Hensarling of Texas, House Ways and Means Committee Chairman Dave Camp of Michigan, and House Energy and Commerce Committee Chairman Fred Upton of Michigan.

Senate Minority Leader Mitch McConnell, R-Ky., named his deputy, Jon Kyl of Arizona, Patrick Toomey of Pennsylvania, a former head of the conservative Club for Growth, and Rob Portman of Ohio, who headed the Office of Management and Budget under former President George W. Bush.

All six Republicans have signed a pledge written by Grover Norquist, the president of Americans for Tax Reform, not to raise taxes. All six Democrats on the supercommittee are staunch defenders of Social Security, Medicare and Medicaid, and say that tax revenues have to be part of the deficit-reduction conversation.

“They’re all very knowledgeable about budget stuff, but whether they’ll be willing to make compromises, I don’t know,” said Robert Bixby, executive director of the Concord Coalition, a nonpartisan group that works on fiscal issues. “I would have liked to have seen people that have been part of efforts to forge bipartisan consensus.”