The “super committee” was already facing high expectations, but Friday night’s downgrade of U.S. debt has placed an even greater burden on congressional leaders as they make their selections for the deficit-reduction panel over the next week.

With an Aug. 16 deadline ahead for making the 12 picks, the top four congressional leaders have so far held their cards close to the vest, not publicly declaring which lawmakers will be tapped for the committee. It’s not even clear whether the leaders will announce their selections on the same day, at the same hour, or if they will dribble out over the next week.

Each of the big four — House Speaker John A. Boehner (R-Ohio), House Minority Leader Nancy Pelosi (D-Calif.), Senate Majority Leader Harry A. Reid (D-Nev.) and Senate Minority Leader Mitch McConnell (R-Ky.) — will select three lawmakers for a 12-person committee divided evenly on party lines. Their mission will be to come up with at least $1.2 trillion more in spending cuts, with $1.5 trillion a more desired outcome.

But there is no upward limit to how much they produce in savings and no restriction as to how they come up with the savings, through increased tax revenue or cuts to entitlement programs. The make-up of the committee could tilt the panel’s final report — due Nov. 23 — in one direction or the other.

If at least seven of the 12 vote for a final proposal, that legislation gets a fast-track consideration in the House and the Senate. Votes based on simple majorities — no Senate filibuster allowed — would send that legislation to President Obama. If they end in deadlock, that would set off the “trigger” of $1.2 trillion in cuts allocated evenly among the Pentagon’s budget and programs for the middle class.

Here’s a rundown of the leading contenders for the panel, broken down by party caucus:

House Republicans

* Frontrunners: Reps. Paul Ryan (Wis.), David Camp (Mich.), Jeb Hensarling (Tex.) and Peter Roskam (Ill.). This handful of lawmakers come from three critical panels that are in the legislative sweet spot of which issues the super committee will have to deal with: Budget, which Ryan chairs; Ways and Means, the tax and entitlement panel which Camp chairs; and Financial Services. Ryan, 41, has become the face of the GOP on all things related to fiscal issues, as his proposed 2012 budget became a rallying cry for both parties — Republicans touted it and Democrats tried to throw it around the GOP’s neck. Camp and Ryan have something of a rivalry, as the budget chairman achieved a very high profile with proposals that Camp later dismissed as non-starters because they could never get through a Democratic-controlled Senate.

Ryan and Camp have served on the Bowles-Simpson commission, and they voted against the panel’s recommendation of $4 trillion in savings through a mix of increased revenue and entitlement cuts. Hensarling and Roskam are junior members of Boehner’s leadership team, and both men are close to House Majority Leader Eric I. Cantor (R-Va.), who emerged from this summer’s negotiations as the party’s leading opponent of new taxes.

* Wild card: The freshmen. Boehner may look to appeal to the class of 87 freshmen Republicans by selecting them for the choice assignment. If so, someone like Rep. Diane Black (R-Tenn.) might fit the bill, as she is a member of both the Budget and Ways and Means committees and is well-liked by leadership.

Senate Democrats

* Frontrunners: Sens. Patty Murray (Wash.), Jack Reed (R.I.), Max Baucus (Mont.) and Kent Conrad (N.D.). Murray is the most natural choice for Reid; she has been in party leadership for more than four years, the highest-ranking woman in the Senate, and she is next in line to chair the Budget Committee. The only mark against her getting the nod is that her current leadership post — chairman of the Democratic Senatorial Campaign Committee — is a political post and it might send the wrong signal by inserting the campaign chief in such a key policy spot. Baucus is chairman of the Finance Committee, with oversight of tax-and-entitlement policy, but he has been involved in debt negotiations over the summer. Reed is a senior member of the Banking Committee and regarded on both sides of the aisle as one of the chamber’s hardest workers.

In an interview with The Washington Post, Reid said he would “consider everyone” but did not particularly endorse the “Gang of Six,” the bipartisan group of senators that advocated a plan along the lines of Bowles-Simpson. If that’s the case, it might rule out Conrad, the Budget chairman who was a member of the “Gang” and the commission.

* Wild card: the young turks. For the past three years, Reid has always looked behind his back at the hard-charging classes of 2006 and 2008 and those that won appointments in early 2009. That group of more than 20 relative newcomers has been looking for more sway inside the caucus, and Reid may appoint someone such as Benjamin Cardin (D-Md.), who won in 2006 and has a relatively safe path to reelection next year. Cardin is a member of the Budget panel and he’s well-regarded by liberals.

Senate Republicans

* Frontrunners: Sens. Jon Kyl (Ariz.), Rob Portman (Ohio) and Jeff Sessions (Ala.). Just before he left town for the five-week summer break, Kyl paid a visit last Tuesday with McConnell. The GOP leader smiled and didn’t say a word when asked by The Post whether his meeting with Kyl, the No. 2 Republican, was about the super committee. Kyl is a senior member of the Finance Committee and is considered a strong conservative, and he’s retiring after next year. He has served as a lead GOP negotiator on the debt issue.

Portman is such an obvious choice that it might not happen. He’s the former budget director for the Bush White House,was a member of the Ways and Means Committee when he was a member of the House, and is a member of the large freshmen class of 2010 senators that McConnell would like to appease. Some view Portman as somewhat moderate, but his profile — hailing from the key presidential swing state — suggests that he might not make his first act on the national stage be in support of a deal that most Republicans hated. Sessions is the Budget Committee’s ranking Republican.

* Wild card: the tea party. McConnell could make a play to appeal to those senators who have developed respect among tea party activists. He has had a long-running feud with Sen. Jim DeMint (S.C.), so DeMint stands no chance of getting the nod. More plausible would be Sen. Pat Toomey (Pa.), a former Wall Street executive who has led recent efforts to suggest that the government would not default even if the debt ceiling were not raised.

House Democrats

* Frontrunners: Reps. Chris Van Hollen (Md.), Allyson Schwartz (Pa.), Xavier Becerra (Calif.) and Norm Dicks (Wash.). Van Hollen is the top Democrat on the Budget Committee and has been given the role of chief antagonist to all things related to Paul Ryan’s budget. If Ryan is on the super committee, Pelosi will surely want Van Hollen on that panel. Schwartz is a veteran who graciously stepped aside at Budget when Pelosi went looking for a new assignment for Van Hollen, who had chaired the campaign committee for four years. She is the highest-ranking female Democrat on the Budget or Ways and Means panels.

Becerra is the party’s highest-ranking Latino, and Dicks, as the top Democrat on the Appropriations Committee, knows the Pentagon’s budget better than anyone and would be able to argue for action rather than setting off the trigger.

* Wild card: Pelosi’s best friend. Rep. George Miller (Calif.) is the top Democrat on the Education and Workforce Committee, is considered Pelosi’s best friend in Congress and is also considered a liberal warrior. A Miller appointment would signal that Pelosi wants to keep very close tabs on the committee and is not likely to endorse deep cuts to programs such as Medicare unless Republicans give in to large tax increases.