By Scott Malone and Patricia Zengerle
BOSTON (Reuters) - A somber Republican crowd watched glumly on Tuesday as former Massachusetts Governor Mitt Romney failed in his bid to unseat President Barack Obama, despite a stubbornly high unemployment rate.
Romney struck a conciliatory note as he conceded. Thanking his supporters, he said he had called Obama and wished the Democrat the best.
"I so wish - I so wish that I had been able to fulfill your hopes to lead the country in a different direction, but the nation chose another leader," Romney said. "And so Ann and I join with you to earnestly pray for him and for this great nation."
The hard-fought election did not end without some late confusion. Television networks declared Obama the winner in the key state of Ohio, but by only a slim margin.
The projected victory prompted questions about whether Romney's campaign would challenge the result.
Romney waited almost two hours after networks called the election before making his concession speech in the ballroom of a Boston convention center. Staffers told waiting reporters there had been an unspecified delay.
But as more swing states, including Virginia, Nevada and Colorado, moved into the Democratic column, aides said Romney would concede shortly.
He appeared on stage at about 1 a.m. and the ballroom fell silent. A small group of men rendered an off-key version of "God Bless America" until Romney was introduced.
In his remarks, Romney called on elected officials to cross party lines and work together.
"I believe in America. I believe in the people of America," he said, pausing in a brief moment of emotion.
The gathering became increasingly quiet as the night progressed.
Romney advisers said they thought their candidate had been hurt by the divisive Republican primary fight, and acknowledged that Obama's campaign had done a good job defining Romney early.
"It was a close race, very disappointing obviously for those of us who supported Governor Romney," said Bob Grady, a Jackson, Wyoming venture capitalist who has been a Romney adviser and worked for President George H.W. Bush.
Grady said Republicans need to rethink their electoral strategy and reach out to immigrant groups. But he said Obama faces a tough challenge in pulling the country together to address the debt and deficit.
The ballroom began emptying when the networks announced that Obama won Ohio.
By the time Obama appeared in Chicago to make his victory speech, the Romney event was empty except for hotel staff and hundreds of reporters.
(Additional reporting by Svea Herbst; Editing by Marilyn W. Thompson and Alden Bentley)