The New House Majority Offers Bipartisanship -- And an Ambitious Agenda

"If we tended to underinvestigate, I think you'll see Democrats tend to overinvestigate," Davis said.

Tuesday's election results could be a boon for backers of wide-ranging changes to U.S. immigration laws, one of the few areas in which Bush differed with House Republicans and sided with a bipartisan Senate approach. The GOP-controlled House had insisted on dealing only with measures calling for tougher border and workplace enforcement, rejecting calls by Bush and the Senate for an expanded guest-worker program and possible pathways to legal status for millions of illegal immigrants. A Pelosi-led House is far more likely to embrace some or all of the Bush-Senate approach, lawmakers said.

"A great deal will depend on whether the president is committed to getting this done," Sen. Edward M. Kennedy (D-Mass.), a champion of the broader immigration rewrite, said in an interview. He said Republicans have overestimated the appeal of a punitive approach to immigration problems, noting the defeat of Rep. J.D. Hayworth (R-Ariz.) -- a chief proponent of deportations and border crackdowns.

Yesterday, Bush said of comprehensive changes to immigration laws: "I think we have a good chance. . . . It's an important issue, and I hope we can get something done on it."

Among the many possible clashes between Bush and the new Congress is the question of whether to permit federal funding for research involving new lines of embryonic stem cells. Bush used his only veto this year to block such legislation, which passed both houses comfortably but not by the two-thirds majority needed to override a veto. The new Democratic-controlled House would appear to remain short of a two-thirds majority favoring more embryonic stem cell research, but the revised political dynamics might force the administration to reconsider its position.

And there will be investigations and hearings, especially into the conduct of the war in Iraq and waste in contracting. Rep. Ike Skelton (D-Mo.) said yesterday the first move he will make as chairman of the House Armed Services Committee will be the reestablishment of the subcommittee on oversight and investigations, abandoned by Republicans when they took the majority.

More than anything else, public unhappiness over the Iraq war powered the Democrats' success Tuesday, according to exit polls, but it was unclear yesterday how much the new Congress will or can do about the conflict. Reid called on Bush to "convene a summit of congressional leaders" to discuss the war. "We've got to work together to change direction in Iraq," he said.

But before such tasks can be tackled, both parties will have to decide who will lead them in a transformed Congress. Rep. Steny H. Hoyer (D-Md.), the House minority whip, launched his battle for the post of majority leader yesterday against Rep. John P. Murtha (D-Pa.), who became a hero to many liberal Democrats with his early calls for a withdrawal from Iraq.

Rahm Emanuel (Ill.), chairman of the Democratic Congressional Campaign Committee, said he would announce today whether he will challenge House Democratic Caucus Chairman James E. Clyburn (S.C.) for the post of House majority whip. If he does, that race would pit the person who can claim a large share of the credit for Tuesday's electoral victories against the only African American in Democratic leadership.

Meanwhile, Hastert, who has been criticized by some for not intervening in the Mark Foley page scandal, announced he will not seek the position of House minority leader next year.

In his wake, a scramble began immediately. Majority Leader John A. Boehner (R-Ohio) will square off with conservative Rep. Mike Pence (R-Ind.), who took a shot at the current leadership in a letter to colleagues saying that "we did not just lose our Majority -- We lost our way. We are in the wilderness because we walked away from the limited government principles that minted the Republican Congress." Rep. Joe Barton (R-Tex.), chairman of the Energy and Commerce Committee, said he may also run.

In Montana, Tester, the state Senate president, held a lead of 2,847 votes -- or 0.7 percent -- over Burns, a three-term senator. Tester declared victory yesterday morning. Burns did not concede, saying, "There is no need to rush to a conclusion when the voters are this close."

"Senator Burns's campaign will do what they think is right when they think it is right," Tester told reporters in Great Falls, Mont. "And I am okay with that. We won this thing."

A spokesman for Secretary of State Brad Johnson, a Republican, said all votes had been counted, except for about 1,000 provisional ballots and an unknown number of military ballots from overseas that could still arrive. The spokesman, Bowen Greenwood, said it is unlikely but not impossible those uncounted votes could bring Burns within a 0.5 percent margin -- approximately 2,000 votes -- and thus allow him to ask for a recount.

Staff writer Blaine Harden in Great Falls, Mont., and staff writer Amy Goldstein in Washington contributed to this report.