The Republican Party, which sits broken and scarred after Tuesday's election defeat to Barack Obama, could face a generation out of the White House if it fails to soften its stance on immigration and appeal to minorities, academics have warned.
Some of Britain's most senior US history professors have said the party faces its worst electoral crisis in 50 years, comparing the situation to the soul-searching that followed Democrat Lyndon B Johnson's runaway victory in 1964.
Barack Obama won the election more comfortably than many pundits predicted, carrying states like Virginia and Ohio where Mitt Romney was expected to be seriously competitive.
Much of that success has been put down to Obama's support among minority communities - he won 93% of the black vote, 71% of the Latino vote and 73% of the Asian vote, according to exit polls conducted by Edison Research.
Professor Iwan Morgan, head of US Studies at the Institute of Americas at University College London, said that the Republican Party can no longer rely on a strategy that gets "angry whites" and "old folks" out to vote.
"The Republicans are very close to the day of reckoning," he said. "They face a prolonged period of minority status unless they adapt to the reality of the new demographic forces in the electorate.
"They have got to attract more Latinos, and that means adopting a sensible policy on immigration reform. They have got to attract more women. Obama had an 11% lead among women."
Prof Morgan questioned whether there was the leadership in the party to bring about that change. "Do they have the nous to change, how will they change and who will lead them? You need the Messiah. The Messiah is not around. There is not even a John the Baptist figure at the moment. So where is change coming from?"
Dr Nigel Bowles, director of the Rothermere American Institute at the University of Oxford, agreed that the Republican Party must adapt to the new shape of the electorate.
"The party is overwhelmingly white, heavily male and largely old," he said. "Romney's problem and Republican aspirants' problems in 2016 and 2020 is that there aren't enough of those people around.
"There's not really a majority of elderly white people in the country. You can't build a presidential coalition on that basis. You have got to reach out to major ethnic groups."
"My prediction would be in 2016, if there is to be a successful Republican candidate he or she will have to have confronted and overcome the problem of immigration."
Dr Bowles warned that without obvious leadership, the Republican Party could descend into a damaging internal clash over its future. "The probability is that a sniping, low level guerrilla war is entirely possible. And that's bad news if it's not closed quickly."
Tony Badger, Mellon Professor of American History at Cambridge University, said you must go back to 1964 to find a time when the Republican Party faced such a challenge to make itself electable for the presidency.
He said: "That Obama lead amongst Latinos is astonishing, given what we know about Hispanic voting. An increasing Hispanic middle class ought to be natural Republican fodder. Actually Hispanic voters are pretty conservative on social issues.
"The Republican politicians who have made a seriously effort to do well there, ie the Bushes, have succeeded. But the reason the Republican Party has never made it further than that is because it does always shoot itself in the foot on immigration."
Prof Badger believes the Republican Party will have to significantly widen its appeal if it is to claim back the White House.
"The acid test is when the Republicans next have their primaries," he said. "Is the base going to be so stupid as to insist that there has to be anything but the decent candidate?
"They came up with Rick Perry, Rick Santorum, Michele Bachmann, Herman Cain, Newt Gingrich. If the Republican base remains like that, and insist on behaving like that, then they have serious problems."