Pat Toomey defeated Democrat Joe Sestak to win Republican-gone-Democrat Arlen Specter's Pennsylvania Senate seat. He voted against the debt deal in early August. (Matt Rourke/AP)

House Speaker John Boehner (R-Ohio) and Senate Minority Leader Mitch McConnell (R-Ky.) on Wednesday announced their picks for the 12-member supercommittee charged with tackling the country’s debt problem.

Of the nine members announced so far, eight voted “yes” on last week’s debt-ceiling deal -- a sign that there exists at least the possibility that the panel will be able to reach a bipartisan agreement. The one delegate announced so far who opposed the debt compromise is Sen. Pat Toomey (R-Pa.).

The GOP picks have scored mixed reviews from budget experts, many of whom are hoping the new committee can produce far greater savings than the roughly $1.5 trillion the panel has been asked to identify.

Steve Bell, the head of the Bipartisan Policy Center and a former Republican Senate staffer, said that overall he has been “pleasantly surprised” by the selections because almost all of them are senior lawmakers with a history of legislating, sometimes across the aisle. “The truth is, you’ve got a lot of IQ points.”

Boehner has tapped House Republican Conference Chairman Jeb Hensarling (Texas), House Ways and Means Committee Chairman Dave Camp (R-Mich.) and House Energy and Commerce Committee Chairman Fred Upton (R-Mich.) to serve on the bipartisan panel.

Both Hensarling and Camp had been viewed as frontrunners for the committee. Hensarling is a junior member of the House Republican leadership team and has a close relationship with Boehner’s deputy, House Majority Leader Eric Cantor (R-Va.), while Camp heads the House panel that oversees tax and entitlement policy. Upton is also a top committee chairman.

Hensarling will co-chair the bipartisan committee along with Sen. Patty Murray (D-Wash.), whose appointment was announced Tuesday by Senate Majority Leader Harry Reid. Reid also selected Sens. Max Baucus (D-Mont.), the Senate Finance Committee Chairman, and John Kerry (D-Mass.).

“The lawmakers I have appointed to serve on this joint committee are proven leaders who have earned the trust and confidence of their colleagues and constituents,” Boehner said in a statement. “They understand the gravity of our debt crisis and I appreciate their willingness to serve on this panel.”

In a statement issued shortly after Boehner’s, McConnell announced that he has tapped Senate Minority Whip Jon Kyl (R-Ariz.), Sen. Rob Portman (R-Ohio) and Sen. Pat Toomey (R-Pa.) to serve on the committee.

Kyl and Portman had both been rumored to be among McConnell’s top picks. Kyl is the Senate’s number-two Republican and was McConnell’s delegate to the debt-reduction talks led by Vice President Biden this spring. Portman is a former director of the White House Office of Management and Budget and also served as U.S. trade representative; a freshman considered a rising star among Senate Republicans, he developed a close working relationship with McConnell throughout the negotiations on raising the country’s debt ceiling.

Toomey, like Portman, is a freshman and is the only member of the panel to vote against the debt compromise reached right before the Aug. 2 deadline. A former Wall Street executive, his selection represents a nod by McConnell to the tea-party movement; he was a leader of the group of House and Senate conservatives who argued that the country would not default on its obligations if the debt ceiling was not raised.

“My main criteria for selecting members was to identify serious, constructive senators who are interested in achieving a result that helps to get our nation’s fiscal house in order,” McConnell said. “That means reforming entitlement programs that are the biggest drivers of our debt, and reforming the tax code in a way that makes us more competitive and leads to more American jobs. The goal is to achieve a result that convinces Americans and the world that we’re committed as a nation to prosperity for all our citizens.”

Baucus and Camp have already been at work, along with Treasury officials, on bipartisan tax reform issues. Upton is a bona fide moderate who had to beat back a “down with Upton” campaign from a tea party-affiliated group in order to claim the committee chairmanship.

And Portman, as a House member a decade ago, forged alliances with some Democrats on the Ways and Means Committee to approve pension reform plans.

However, the panel’s leaders, Murray and Hensarling, hail from the more partisan wings of their respective party caucuses, and, according to former Hill aide Bell, most experts only rate a “25 percent chance” that the group can forge a bipartisan deal that can win approval because of the entrenched partisan atmosphere in the Capitol.

“You’re not part of the team. You’re not part of the tribe,” Bell said, explaining the pressure that will come to bear on the committee members.

Wednesday’s announcements were also noteworthy for who was not selected to serve on the panel. Boehner did not choose House Budget Committee Chairman Paul Ryan (R-Wis.), who has been among his party’s top voices on fiscal issues and was the leader behind House Republicans’ fiscal year 2012 budget.

Ryan said in a statement that he had asked Boehner not to consider him for the panel, as “only the Budget Committee can write legislation to reform the budget process.”

“As Budget Committee chairman, my plan has long been to work on this critical issue throughout the fall,” Ryan said. “This past year has shown that the federal budget process is more broken than ever and needs to be reformed. If we are truly going to put the country’s fiscal house in order, it will not be enough to temporarily reduce what Washington spends. We must permanently reform the process by which working Americans’ hard-earned tax dollars are spent.”

He added that Boehner had selected “three excellent Republican members” for the panel.

Also missing from the panel will be any lawmakers among the “Gang of Six,” the bipartisan group of senators who for months worked to produce their own comprehensive deficit reduction plan, which they unveiled late last month. Some members of both parties’ bases had viewed the Gang’s proposal with skepticism, as it advocated for a broad approach that included both entitlement cuts and tax increases. But the plan has also been viewed by many members as the most-detailed plan thus far to tackle the country’s debt.

Boehner also did not choose any members from among the 87-member class of House Republican freshmen.

House Minority Leader Nancy Pelosi (D-Calif.) has not yet announced her picks for the supercommittee; leaders have until Aug. 16 to announce their choices.

Paul Kane contributed to this report

More on PostPolitics

Republicans smell blood in presidential race

Fact Checker: Obama’s claim that the debt problem can “go away”

GOP wins four Wis. recall races