LONDON - British newspapers on Thursday feted US president-elect Barack Obama's victory as a sign of a "transformed" America but warned that the country's first black leader had a monumental task ahead.
They said the euphoria triggered by Obama's historic win would soon give way to the hard work of presidential politics, with one paper referring to British prime minister Tony Blair's fall from grace after a landslide victory in 1997.
"It was impossible not to feel that the world was a slightly better place -- that civilisation had taken a significant step forward," the Daily Mail newspaper wrote.
But it warned that "for a brief honeymoon period, Obama will be given the benefit of the doubt. After that, he will be judged on his actions."
"As we know from the Blair experience, hope in a new leader can soon turn to bitterness and cynicism if he does not live up to his promise."
Despite leading his party to three successive general election victories, Blair was forced to signal his resignation after a rebellion by MPs from his own party, eventually leaving office in June 2007.
Other newspapers mostly focused on the historical significance of Obama's triumph.
"If there are moments when history pivots, this is one," the Financial Times wrote in its editorial, describing his victory as "inspiring and inspiring".
"To challenge and reassure at the same time requires political talent of the highest order. Mr Obama is a once-in-a-generation politician."
With results confirmed from 48 states and the District of Columbia, Obama joined a select club of presidential victors to win more than half of the popular vote, tallying 52 percent to 46 percent for the Republican.
The Independent, meanwhile, described his victory as a watershed for the United States, and added that the levels of participation in the election showed showed the vibrancy of American democracy.
"Whatever comes next, America has been transformed."
"For all the cruelties and prejudices of the past, it speaks well of the United States that such a victory came to pass -- or, as the president-elect expressed it with more poetry, the true genius of America is that America can change," the paper wrote.
"Thanks to McCain v Obama, it (American democracy) is now alive and well, and vigorous, perhaps, as never before."