And Now, Madame Speaker

Ebullient Democrats declared victory as months of brutal campaigning yielded one big prize they had been fighting for Tuesday night: control of the House of Representatives in the next session of Congress, under the first female Speaker of the House, Nancy Pelosi. With results projected in most races, the Democrats were set to win key battles in Connecticut, Indiana, Ohio, Pennsylvania and Arizona, capitalizing on anger against the war in Iraq, Republican scandals and a broad anti-incumbent sentiment.

The victory was not total. In Kentucky and Virginia, both red state redoubts, incumbent Republicans held off tough challenges. But a large geographical shift of voter sentiment toward the Democrats in the Northeast and Ohio Valley was enough to push Democrats over the top . And two key wins in Arizona spelled trouble for the G.O.P. in the southwest and California.

With momentum at their backs, Democrats were set to claim a gain of between 20 and 35 seats, well beyond the 15 they needed to take control. That in turn will give Pelosi a mandate for change to launch the kind of tough anti-G.O.P. agenda the White House and their Republican allies on the Hill had feared. "The campaign is over," Pelosi shouted on Election Night, grinning with confidence in front of hundreds of roaring supporters blocks from the Capitol in Washington D.C. "Democrats are ready to lead!" A hoarse Rep. Rahm Emanuel, head of the Democratic Congressional Campaign Committee, told the cheering supporters, "We'll give you the government that no longer lets you down." And he pledged to "reach across the partisan divide."

That familiar victor's olive branch did little to placate worried Republicans, who are preparing for life under a Democrat-led House, which will mean the loss of subpoena power and committee chairmanships that comes with defeat. G.O.P. strategists blamed the defeat on two factors: badly run races in the northeast and the wave of scandal that overtook the party. "The scandal seats clearly hurt us and our performance in the northeast was not good," said National Republican Campaign Committee spokesman Carl Forti. But he claimed some solace in races the party appeared likely to pull out in Connecticut and Georgia.

The first indication of real trouble for the Republicans on Tuesday came with the loss of Kentucky's third district, where the competent and attractive five-term incumbent Anne Northup was unseated by Democrat John Yarmuth in a race that focused on Iraq and the performance of the Bush administration. Another key early indicator of discontent with Bush and Iraq came with the loss of twelve-term incumbent Nancy Johnson's solid seat in Connecticut.

Scandal took a predictable toll on the G.O.P. In Pennsylvania, 20-year House veteran Curt Weldon fell to the square-jawed Admiral and Clinton administration official, Joe Sestak. Also in Pennsylvania, political newcomer Christopher Carney downed four-term incumbent Don Sherwood, who pleaded with voters to forgive his marital infidelity, apparently to no avail. In Ohio, the Democrat Zack Space pummeled Joy Padgett, the hand-picked replacement of Rep. Bob Ney, who resigned amid an investigation of his ties to disgraced lobbyist Jack Abramoff.

And in a key race in Florida, popular State Senator Ron Klein ousted the old bull Clay Shaw, as powerful a congressman as the State of Florida has. That loss will surely be read as retribution for the Bush Administration's push to partially privatize Social Security, and will also be seen as a rebuke to the G.O.P. for the Foley scandal in neighboring Miami.

Not all battleground races went blue. Top G.O.P. leaders fought off tough challenges in New York and Ohio. Tough pol Tom Reynolds of upstate New York threw off his entanglement in the Mark Foley scandal to beat populist millionaire Jack Davis, and Ohio's Deborah Pryce, a centrist in the House leadership, pulled out her tough race against Mary Jo Kilroy. And in the tight House race in Connecticut's fourth district, Chris Shays was leading Diane Farrell in a death-defying G.O.P. win in hostile territory.

The Democrats' victory will be viewed as historic not just for the size and the breadth of the win. Pelosi will take the helm as the country's first woman Speaker, the person directly behind the vice president for succession to the Presidency, at a moment of key contest between the branches of government and deep divide in the country over the war in Iraq and the fight against international terrorism. How President Bush learns to deal with the gentlewoman from San Francisco will be a key story of the rest of his presidency.