Kerry placed his call after weighing unattractive options overnight. With Bush holding fast to a six-figure lead, Kerry could give up or trigger a struggle that would have stirred memories of the bitter recount in Florida that propelled Bush to the White House in 2000.

Kerry's call was the last bit of drama in a campaign full of it. While Bush remains in the White House, Kerry returns to the Senate, part of the shrunken Democratic minority.

He acted, hours after White House chief of staff Andy Card declared Bush the winner and White House aides said the president was giving Kerry time to consider his next step.

One senior Democrat familiar with the discussions in Boston said Kerry's running mate, North Carolina Sen. John Edwards, was suggesting that he shouldn't concede.

The official said Edwards, a trial lawyer, wanted to make sure all options were explored and that Democrats pursued them as thoroughly as Republicans would if the positions were reversed.

Advisers said the campaign just wanted one last look for uncounted ballots that might close the 136,000-vote advantage Bush held in Ohio.

An Associated Press survey of the state's 88 counties found there were about 150,000 uncounted provisional ballots and an unspecified number of absentee votes still to be counted.

Ohio aside, New Mexico and Iowa remained too close to call in a race for the White House framed by a worldwide war against terror and economic worries at home.

But those two states were for the record — Ohio alone had the electoral votes to swing the election to the man in the White House or his Democratic challenger. A GOP legal and political team was dispatched overnight to Ohio in case Kerry made a fight of it.

Republicans already were celebrating election gains in Congress. They picked up four seats in the Senate, and they drove Democratic leader Tom Daschle from office.

That will be the state of play on Capitol Hill for the next two years, with the chance of a Supreme Court nomination fight looming along with legislative battles.

Republicans also re-enforced their majority in the House.

Glitches galore cropped up in overwhelmed polling places as Americans voted in high numbers, fired up by unprecedented registration drives, the excruciatingly close contest and the sense that these were unusually consequential times.

"The mood of the voter in this election is different than any election I've ever seen," said Sangamon County, Ill., clerk Joseph Aiello. "There's more passion. They seem to be very emotional. They're asking lots of questions, double-checking things."