Some conservatives warned colleagues they risked annihilation by refusing to change and appeal to the women, younger and ethnically diverse voters who had stood by Mr Obama since 2008.
Chief among moderates' fears was Mr Romney's lack of support among Hispanic voters. Senator Marco Rubio, who is Cuban-American, called on his party to heal the damage done to its image among ethnic minorities, many of whom were repelled by its tough stance on immigration.
Bob McDonnell, the Republican governor of Virginia -- a traditionally conservative state that Mr Obama won again, backed by a rising Hispanic population -- said newcomers were crucial to economic recovery and must be embraced.
"We're a nation of immigrants," he said. "We ought to find more ways to have legal immigrants come here."
Even Erick Erickson, founder of the grassroots website RedState, criticised Mr Romney for his "atrocious" efforts among Latinos. "Frankly, the fastest-growing demographic in America isn't going to vote for a party that sounds like a party that hates brown people," he said.
However, Mr Erickson also led a right-wing dismissal of suggestions that the Republicans should shift to the centre on economic or other social issues, saying instead that Mr Romney had been "pathetic at defining a real, right-of-centre alternative" to Mr Obama.
"Compromise? Like hell," he said. "We're going to keep fighting. The next two years will set the vision of a more populist-oriented conservatism."
A Republican official in Washington spoke for many defiant colleagues by predicting that the party would not need to change because Mr Obama would drive the Democrats to disaster in a second term. "He'll damage the Democrat brand so badly that his successor won't be able to win," he said. (© Daily Telegraph, London)