Fresh from a victory that stunned even their optimistic partisans, Republicans brushed critics aside with a vote that would have been hard to imagine before the Nov. 2 elections: changing their House rules to allow leaders to stay in their post even if criminally indicted.
Democrats, for their part, showed that they are also in a new postelection place. This week, they quietly elected new leadership while bracing for fights with the GOP on everything from big staff reductions to a rule change that would limit their power to block judicial nominations.
After four years of near parity on Capitol Hill, both parties show signs of settling into the mind-set of majority or minority roles - and the dangers each includes.
The risks are most obvious for Democrats. Their challenge is to avoid getting used to being the party out of power - and keeping talented people interested enough to stay in the game. Some now talk openly of a long-term decline.
"This campaign was another chapter in a 40-year slide for the Democratic Party since the Lyndon Johnson landslide of 1964," when Democrats had 2-to-1 majorities in both houses of Congress, says Al From, CEO of the Democratic Leadership Council. "If we are to be a majority party again, we have to change."
But in the cyclical world of US politics, dangers loom for majority party too. The classic error is overreaching.
In 1994, Republicans won their way back to power in the House on a crusade to topple a party grown arrogant and corrupt after four decades in power. Yet, once in power, they gradually rolled back many of the reforms proposed at that time: a ban on gifts from lobbyists, term limits for the House speaker, rules protecting minority rights, and, most recently, a party rule requiring leaders to step down after a criminal indictment - as now seems possible for House leader Tom DeLay of Texas.
"When you have a victory, there is a temptation to a sense of arrogance. It makes you less surefooted, wary and prudent. There's a real danger of overreach," says Ross Baker, a political scientist at Rutgers University in New Jersey.
Despite a now-wider Republican margin of control in both the House and Senate, Democrats aren't slinging stones at fellow Democrats, not yet. Election of new leadership was quick and all but uncontested. Sen. Harry Reid of Nevada easily assumed the mantle of Sen. Tom Daschle, after serving as his deputy for eight years. House Democratic leader Nancy Pelosi was reelected without competition.
But the real struggle for Democrats on Capitol Hill is playing out on more private turf: Whether to stay on in a GOP-controlled Congress and fight it out - or exit to greener pastures.
In some ways, the mood shift for both parties seems sharper than raw numbers dictate. Domestic or foreign setbacks for Republicans could put both chambers of Congress back in play for Democrats in 2006. But that's not how it feels now.
"It's just demoralizing to be a Democrat in the House or Senate now. All the incentives are against staying in, if you are really ambitious," says Julian Zelizer, a congressional historian at Boston University.
The prospects seem bleakest in the Senate, after losing all five open seats in the South in 2004 and with more races in GOP-leaning states in in 2006. "It's hard to see things getting better anytime soon," says a senior Democratic staffer.
More desirable to be governor?
For some Senate Democrats, the choice is whether to start lining up a run for governor - historically, a stronger platform for a presidential run than the US Senate. The most likely prospect to jump ship is Sen. Jon Corzine (D) of New Jersey. The resignation of New Jersey Gov. James McGreevey (D) this week could draw Senator Corzine into a run as early as 2005. A former chairman of Goldman Sachs, Corzine self-financed the most expensive US Senate campaign ever and would be a strong favorite to win the governor's race.
"If I leave, it won't be because I don't love the Senate," says Corzine, the outgoing chairman of the Democratic Senatorial Campaign Committee. "There's a potential to raise standards in New Jersey and a big agenda on homeland security, the economy, and healthcare not unlike what we have here in the Senate."
Aides to four-term Sen. Christopher Dodd (D) of Connecticut - who backed off a possible challenge to Reid for the leadership post - say he has not ruled out a run for governor in 2006.
A big question: Where will the new crop of congressional candidates come from?
"Democrats have to convince people we haven't heard of yet in the states to run for office and put their careers in this institution," says historian Zelizer.
With each year in the minority, that job gets tougher. Democrats are likely to face reductions from near parity with Republicans in congressional staffing and funding toward a more traditional 2-to-1 majority/minority ratio.
GOP's challenge may be hubris
Meanwhile, the challenge for ascendant Republicans is to avoid overreach. Critics say that Wednesday's House Republican conference vote to change its ethics rules to protect leadership is a step in that direction. "It is ironic that 11 years ago, House Republicans adopted the same rule scrapped today in an effort to draw attention to Democrats' ethical problems," says a statement by Common Cause and Citizens for Responsibility and Ethics.
Republican leaders say that the rule change is a protection against politically motivated indictments, possibly involving majority leader DeLay.
"We've seen gross politicization of this indictment process," says Rep. David Dreier (R) of California, chairman of the House Rules Committee. "If we had not done this, it would have enhanced the prospect of an indictment."
Still, some Republicans worry that the move is a step in the wrong direction. "If you are indicted, you should step down," said Rep. Christopher Shays (R) of Connecticut, after the vote. "Too many of our members are slipping into business as usual, saying 'We're going to do it just like the Democrats do it.' " House Democrats, who do not currently have a requirement for indicted leaders to step down, say they will quickly vote one.
Another indicator of a party settling into majority control is how aggressively it tries to restrict the voice of the other party. At the peak of their power, Democrats allowed relatively open amendment process on bills only 44 percent of the time. Under Republican control, that indicator has slipped to 26 percent, according to data compiled by the Woodrow Wilson International Center for Scholars.
"When Republicans took power, we said we were not going to act like the Democrats, that we could carry our case in an open process. But ... we didn't realize how difficult it would be to hold a majority together," says a former House GOP aide.