WASHINGTON - U.S. President George W. Bush congratulated Barack Obama, whose dominant White House win was built on presenting himself as a change from the policies of the two-term Republican.

Said Bush to his Democratic successor Tuesday: "What an awesome night for you."

"I promise to make this a smooth transition," Bush told Obama at 11:12 p.m. EST, shortly after the Illinois senator captured enough electoral votes to cement his status as president-elect. "You are about to go on one of the great journeys of life. Congratulations and go enjoy yourself."

As usual in American presidential politics, the losing candidate -- in this case, Republican John McCain -- was gracious in defeat. So was Bush, who though not on the ballot this year found his name immersed in the race to replace him, as both Obama and McCain sought some distance from the administration.

"Mr. President-elect, congratulations to you," Bush told Obama according to a White House account of the call. "What an awesome night for you, your family, and your supporters."

Bush also called McCain, who pledged in a concession speech to support Obama and rallied his supporters to do the same.

The president told McCain that his statement was classy, according to his aide.

"John, you gave it your all. I'm proud of you, and I'm sorry it didn't work out," Bush told McCain, according to White House press secretary Dana Perino. "You didn't leave anything on the playing field."

The two men had battled fiercely for the Republican presidential nomination in 2000, and since became allies, although uneasy ones at times.

Vice-President Dick Cheney also called and congratulated Obama's running mate, Sen. Joe Biden of Delaware.

The president planned a Rose Garden statement about the election at 10:40 a.m. EST on Wednesday.

Outside the White House late Tuesday, roughly 2,000 people or more chanted and cheered on Pennsylvania Avenue, revved up by Obama's soaring victory.

Off the ballot but still in voters' minds, Bush watched election results come in like the rest of the country.

He had privately told his friends and advisers during a dinner toast: "May God bless whoever wins tonight."

Even before one vote was counted, this result was clear: The presidential race was a verdict on the two-term president, too.

The president's approval ratings have hovered near historically low levels -- it was just 26 per cent in an AP-GfK poll conducted a couple of weeks before Election Day -- and he was a factor in voters' decision-making no matter how much he tried to stay out of the race.

In preliminary results from an Associated Press exit poll of voters on Tuesday, Bush and the Democratic-run Congress got low marks from voters. Only about one in four approved of how Bush is handling his job, and Congress got about the same.

Bush kept the lowest of profiles on Tuesday.

He voted absentee several days ago, so there was no video of him at his precinct, no statements to reporters, no public appearance whatsoever.

Bush spent the early part of his evening in the White House residence, hosting a small dinner with his wife, Laura, in the Old Family Dining Room. Several close friends and members of Bush's senior staff were invited. Bush thanked his guests for their friendship and their work.

There was, in fact, a celebration for Bush and his guests. Tuesday was the first lady's 62nd birthday. The president gave her earrings.

For many months, Obama seized on Bush's unpopular standing to make him a political liability for McCain, who in turn separated himself aggressively from the face of his own party as the campaign closed.

In the exit polling, of the voters who said they approved of Bush's performance, about nine in 10 went for McCain. Almost seven in 10 of those opposing Bush broke for Obama.

Also, about half those polled said that McCain would continue Bush's policies -- and those with that view went for Obama in big numbers.

Tuesday marked the first time in 14 years -- a period when Bush twice won the Texas governorship and the presidency -- that he was not on the ballot.