Even though they're a minority among partisans on both sides of the aisle, moderate lawmakers have flexed their political muscle lately, changing the course of Senate votes.

In the judicial nominee fight that just subsided, Republican centrists broke from the party line and defended the right of Democrats to use the filibuster against President Bush's judicial nominees. Moderate Democrats split from their leadership and agreed to give the president's more controversial candidates an up-or-down vote.

Elsewhere, even in the face of a veto threat, many House Republicans defied their anti-abortion constituency on Tuesday and stood shoulder-to-shoulder with Democrats to support embryonic stem cell research (search). The Senate looks set to follow course.

In February, after considerable angst by many House Democrats over the civil rights implications, 42 members of the party agreed to tighten the rules for states giving licenses to illegal immigrants. Likewise, 50 House Democrats agreed to change the rules on filing class action lawsuits to prevent judge shopping in state courts. Both issues had near universal support from Republicans, who were strongly encouraged by the White House and GOP interest groups.

Some political observers say these recent examples of bipartisan unity don't necessarily constitute a "moderate resurgence," but more likely represent a brief reprieve in the usual partisan duel that has characterized Capitol Hill in recent years. Nor does it mean forthcoming proposals from Bush will be opposed or supported strictly along party lines.

"The 'Gang of 14' was a diverse group, by no means entirely moderate or centrist in their views," Thomas Mann, senior fellow at The Brookings Institution, said of the Senate group who negotiated the deal to maintain filibusters and confirm Bush's nominees. "Stem cell research attracts a broad array of supporters, including some pro-life conservatives … Bush's difficulties on other matters — Social Security, immigration, medical malpractice — flow from the unpopularity of his proposals."

FOX News political analyst Michael Barone said it's more likely that a group like the Gang of 14 could be a player in, rather than an impetus for, responding to major legislation and determining a course of action to take.

"There's often a role for these people. I don't think it's totally unprecedented," said Barone, a reporter with U.S. News and World Report and author of the Almanac of American Politics.

Staying Along the 35-Yard Line

In the judicial filibuster deal, 14 senators — seven from each party — decided they were sick of the partisan bickering that had nearly paralyzed the Senate. They met behind closed doors to agree on a deal that prevented the disruption of further Senate business. The gang came under fire from critics for creating an agreement that many complain doesn't do enough for either side.

Some pundits say the more partisan Congress becomes, the more the so-called moderates may try to exercise their centrist muscle.

"The White House has been putting out the message that they do not feel constrained that the centrists have taken control from the Republican leadership," FOX News political analyst Juan Williams said on Wednesday. "They don't feel that they have to nominate a moderate [to the judicial bench]. They have been defiant in saying that the president still will nominate a true conservative for a Supreme Court opening, but if he does, I think there's a risk that some of the Republican moderates," people like Sens. Lincoln Chafee or John McCain, may feel squeezed and could opt out of voting with the majority.

Chafee of Rhode Island voted against Bush nominee Priscilla Owen (search), one of the seven nominees at the center of the debate. McCain, the Arizona Republican, who is renowned for not letting himself get too ensconced in the cement holding his party's line, was one of the lead senators who brokered the filibuster deal.

In an interview with FOX News on Thursday, McCain said the group attempted to break the gridlock in part, because, according to polls, only 33 percent of Americans approve of the job Congress is doing "because they don't like to see us fighting."

"Fourteen people and I was not the leader, all of us got together … we wanted to preserve the Constitution, we wanted to move forward," said the former Vietnam POW.

Click here to watch FNC's interview with Sen. John McCain.

Meanwhile, 50 House Republicans split from Bush and voted Tuesday in support of a bill that would expand federal funding for embryonic stem cell research, showing that many in the GOP are more interested in furthering research that cures diseases such as Parkinson's and Lou Gehrig's than they are in appeasing the White House, which argues that harvesting embryos is like killing life at its start.

"I don't support cloning, but I want to save life," Rep. Randy Cunningham, R-Calif., said during debate. "We're this close to stopping juvenile diabetes and there's other embryos that are tainted so bad that you would not want to implant those. And they want to study those so that they can stop those childhood diseases."

Congressional lawmakers have marched to their own beat on some other issues.

The Republican-controlled Senate this month, for example, defied the threat of Bush's veto in order to pass a $295 billion highway bill; the White House said it was too expensive in a time of war and debt.

Elsewhere, the House New Democrat Coalition, which has traditionally supported trade deals, has said the Central American Free Trade Agreement (search) doesn't sufficiently protect workers' rights in Central America and condemned the administration for cutting support for U.S. workers displaced by trade.

So-called moderates and other lawmakers not willing to simply fall in line may prove critical in forthcoming debates on some of the president's proposals, including Social Security reform, CAFTA and the budget.

"A quarter-century ago, most members of Congress could be broadly characterized as being in the center — ranging inward from at least the 35-yard line, in a classic bell-curve distribution," Norm Ornstein, a political expert with the American Enterprise Institute, wrote in an editorial in the Capitol Hill newspaper Roll Call on Wednesday. "Today's Congress has a pretty barred mid-field area, with far more members hovering around the 10-yard line and a whole lot behind each goal post … [but] votes from the dwindling number between the 35-yard lines are still crucial."

Barone noted that past close votes on trade-promotion authority, for example, have "squeezed out votes from people in both parties." The highway bill passed by the Senate earlier this month with a vote of 89-11, with a majority of Republicans joining Democrats in giving the thumbs-up to a package that the White House said was $11 billion more than it wanted.

"It is not true that all legislative activity has been conducted along strict partisan lines," Barone said. "In the last year or two, a lot of it has been across party lines in different ways."

Paying the Price

But as in all things Washington, moderate Republicans and Democrats may have to pay a political price for daring to go places where the majority of their party won't.

Christian conservatives are vowing retribution at the polls for senators from both parties who forged the judicial nominee deal, for example.

James Dobson, founder of Focus on the Family, called the judicial nominee deal "a complete bailout and betrayal by a cabal of Republicans." He promised that voters will remember "both Democrats and Republicans who betrayed their trust."

Groups like Focus on the Family, the Family Research Council and the Iowa Christian Coalition, which is based in the state whose quadrennial caucuses serve as the launching pad for many presidential hopefuls, stated that those who brokered the deal won't get help from them in any future political ambitions.

But how valid that threat is remains to be seen, since conservative voting blocs didn't influence the vote for many of the lawmakers involved in the filibuster deal. For example, Maine's two Republican senators were party to that deal but Maine only gave Bush 44 percent of its vote in 2004. Likewise, in Rhode Island, Bush only got 34 percent of the vote; Republican Sen. Lincoln Chafee was also part of those negotiations.

Groups like the Congressional Black Caucus and the National Organization for Women, meanwhile, are "just as angry as they are on the right," McCain noted.

On the other hand, moderate maneuvering might help people like McCain, whose name is always floated as a future White House contender.

"You are seeing the big dogs in the Republican Party trying to cement their positions as leaders," Williams said. "McCain came away as the man who was able to make a deal ... John McCain says, 'I appeal to the mainstream, and I'm not afraid of the primaries, of the right wing of the party.' (He is) saying, 'I didn't back the conservative judges.'"

But McCain himself says his moves to avert a judicial showdown have nothing to do with any future political race.

"If my presidential ambitions were the motivation for this, one, I never would have come out against the nuclear option which I did ... personal ambitions did not play a role in this decision making. I think most observers would have said I should have gone the other way."

Arguments have also been made that moderate Republicans may be trying to help rehabilitate the party's image, which has been hurt in recent months by debates such as the fate of Terri Schiavo, the now-deceased, severely brain-damaged woman who was brought to the forefront of "culture of life" politics.

After a divided Congress intervened by trying to get a federal court to review Schiavo's case, the GOP took a beating in public opinion polls, where many Americans disagreed with their decision to interfere in a case that the Supreme Court had previously declined to hear. Later comments by House Majority Leader Tom DeLay (search) advocating retaliation against judges who agreed that Schiavo should have her feeding tube removed also angered many voters.

"Some Republicans have an electoral motive to make distinctions between themselves and the image of the main body of the party," Barone said. "I think all these people are acting out of some combination of calculation and conviction and you're never sure quite what percentage is calculation and what percentage is conviction."