WASHINGTON — Republican leaders in the House of Representatives and the Senate appointed six conservative lawmakers Wednesday to the so-called "super committee" that's charged with finding ways to trim the federal deficit by more than $1 trillion by year's end.

Clockwise, from top left: Kyl, Portman, Toomey, Upton, Hensarling and Camp were selected by Republican leaders. (AP Photos) Analysts immediately suggested that the selections increased the odds that the panel will be unable to reach a compromise that can win Congress' approval.

The six, along with three Senate Democrats whom Senate Majority Leader Harry Reid, D-Nev., tapped Tuesday, bring a diverse knowledge of fiscal affairs to a committee created as part of last week's deal that allowed Congress to approve a measure to raise the federal debt ceiling.

But they also carry some fixed beliefs that may make reaching compromise on spending cuts and tax issues difficult. Three more Democrats, to be selected by House Minority Leader Nancy Pelosi, D-Calif., are to be named to the panel by Tuesday.

The Republican senators whom Senate Minority Leader Mitch McConnell, R-Ky., named to the panel are Jon Kyl of Arizona, Patrick Toomey of Pennsylvania and Rob Portman of Ohio. Toomey and Portman are serving their first terms in the Senate.

House Speaker John Boehner, R-Ohio, chose three experienced chairman for the panel: Republican Conference Chair Jeb Hensarling of Texas, Ways and Means Committee Chair Dave Camp of Michigan and Energy and Commerce Chair Fred Upton of Michigan.

On Tuesday, Reid announced that Sens. John Kerry of Massachusetts, Max Baucus of Montana and Patty Murray of Washington state were his super committee choices.

Murray will serve as a co-chair of the panel, along with Hensarling.

In announcing his picks, McConnell said he was seeking "serious, constructive senators who are interested in achieving a result that helps to get our nation's fiscal house in order."

In a nod to the possibility that reducing the deficit might include both cuts in spending and additional revenue, McConnell said achieving that would mean "reforming entitlement programs ... and reforming the tax code in a way that makes us more competitive and leads to more American jobs."

Boehner called those he'd selected "proven leaders who have earned the trust and confidence of their colleagues and constituents."

Former Sen. Alan Simpson, R-Wyo., who co-chaired a bipartisan presidential deficit commission whose recommendations last year largely were ignored by both Democrats and Republicans, said he had "no idea" whether the panel would be able to reach an agreement "but at least they are new faces looking at the same old figures."

"Let 'em just get in a big old burlap sack and get scratching," he said.

Under the Budget Control Act of 2011, which President Barack Obama signed last week, the committee must make its recommendations by late November. Then Congress must vote on the package by Dec. 23. If the committee and full Congress can't agree on at least $1.2 trillion in deficit reductions, automatic spending cuts would take effect in 2013.

The Democratic and Republican congressional leaders said the lawmakers they'd selected could rise above political ideology to make hard choices and reach consensus. But some budget analysts and political experts expressed doubts Wednesday that the panelists can check their ideologies at the door.

"I'm not terribly hopeful, because you have people who've spent a career saying no cuts for entitlement programs or no new taxes," said Robert Bixby, the executive director of the Concord Coalition. "I guess that gives them the Nixon-goes-to-China approach if they actually do come to a compromise, but you have some pretty strong anti-compromise voices on that panel so far."

Two of the House Republicans, Hensarling and Camp, and one of the Senate Democrats, Baucus, served on the 19-member bipartisan National Commission on Fiscal Responsibility and Reform, which Simpson chaired along with former Clinton White House Chief of Staff Erskine Bowles.

All three voted against the panel's recommendations. At the time, Camp and Hensarling said the commission was a launching pad for tax increases, while Baucus said the commission's recommendations would hurt rural America by reducing retirement and health care benefits for older people and veterans, raising gasoline taxes and cutting farm subsidies.

All six of the Republicans named to the congressional panel have signed a pledge written by Grover Norquist, the president of Americans for Tax Reform, not to raise taxes.

Toomey is a flat-tax advocate and a former head of the Club for Growth, which supports making permanent the tax cuts implemented by former President George W. Bush. Portman served as the director of the Office of Management and Budget under Bush.

"That doesn't bode well for some sort of a grand bargain here that would really get at the heart of the problem," Bixby said. "I'm not encouraged from that sense."

Murray, who chairs the Democratic Senatorial Campaign Committee, and Kyl, the No. 2 Republican in the Senate, engendered worries as well.

"I worry about Jon Kyl," said Andrew Fieldhouse, a federal budget-policy analyst at the Economic Policy Institute, a liberal research center. "The conservatives have vowed to only appoint Republicans who will oppose any and all tax increases, and I imagine those picks were chosen with that in mind."

Simpson and other conservatives expressed the same sentiments about Murray.

"Patty Murray is a very partisan person," Simpson said. "She's going to remain a very partisan person. She's got a lot at stake."

But David Addington, the vice president for domestic and economic policy at the conservative Heritage Foundation, was more upbeat about the committee's prospects for success.

"I fully understand being pessimistic, but this committee is different" from earlier presidential commissions, Addington said. "This time it's the House and the Senate. It's their own committee, and they have to treat it much more seriously than when it was just an outside group making recommendations that they can ignore."

(Rob Hotakainen and Kevin G. Hall contributed to this article.)