WASHINGTON — Counting down to Election Day, Barack Obama appears within reach of becoming the nation's first black president as the epic campaign draws to a close against a backdrop of economic crisis and lingering war. John McCain, the battle-scarred warrior, holds out hope for a Truman-beats-Dewey-style upset.

Whoever wins, the country's 44th president will immediately confront some of the most difficult economic challenges since the Great Depression.

In that effort, he'll almost surely be working with a stronger Democratic majority in Congress, as well as among governors and state legislatures nationwide. GOP incumbents at every level are endangered just eight years after President Bush's election ignited talk of lasting Republican Party dominance.

It's been an extraordinary campaign of shattered records, ceilings and assumptions. Indeed, a race for the ages.

Democrat Obama has exuded confidence in the campaign's final days, reaching for a triumph of landslide proportions.

"The die is being cast as we speak," says campaign manager David Plouffe.

Undeterred, Republican McCain vows to fight on, bidding for an upset reminiscent of Democrat Harry S. Truman's stunning defeat of Thomas E. Dewey in 1948.

Looking back only to early this year, campaign manager Rick Davis says, "We are witnessing perhaps, I believe, one of the greatest comebacks since John McCain won the primary."

The odds for Republicans in 2008 have been long from the start: Voters often thwart the party that's been in power for two terms. And this year, larger factors are working against the GOP: the war in Iraq, now in its sixth year, and the crisis on Wall Street and in the larger economy. Voters deeply distrust government and crave a new direction.

Republicans are girding for widespread losses.

"It's a fairly toxic atmosphere out there," said Nevada Sen. John Ensign, chairman of the Senate GOP's campaign effort. Added his House counterpart, Oklahoma Rep. Tom Cole: "We haven't caught very many breaks."

Democrats are looking ahead to expanded power.

"Things are looking very good," said Maryland Rep. Chris Van Hollen, the head of the House Democrats' campaign committee. New York Sen. Chuck Schumer, chairman of the Senate Democrats' effort, predicted: "We're going to pick up a large number of seats, and that's going to make Democrats very happy."