By Kim Ghattas
BBC News, Boston, Massachusetts
Of all the campaign headquarters, Mitt Romney's must have been the quietest this evening.
Mitt Romney has not seen all the big wins he hoped for
By 2200 Eastern Time (0300 GMT) there had been only two real wins - Massachusetts, which is the former governor's home state, and Utah, a state founded by Mormons and where the Mormon candidate was always expected to win.
But even in Massachusetts, projected results show that John McCain has made quite a dent in Mr Romney's gains.
The mood here is quiet, subdued, almost tense, but everybody is trying to put on a brave face.
A lot of the supporters say they are keeping the faith and waiting for the final results because, as one man said: "We don't believe what the media is saying at the moment, that Mitt is losing."
'Fight goes on'
The strategy of the Romney campaign has been to try to pick up enough delegates to survive Super Tuesday and stay in the race.
Kevin Madden, a spokesman for the campaign, said they were confident that Mr McCain would not be able to lock up the nomination and that they would continue fighting in upcoming primaries, from Kansas to Wisconsin, "district by district".
He tried to explain the McCain gains in Massachusetts, saying it was a natural spill-over from states like New York and New Jersey.
While some states are winner-takes-all, like Utah or Missouri, in other states the delegates are allocated proportionately.
Laurie, one of the supporters at the campaign, said the poor showings were due to the "Huckabee thing" and added, rather angrily, that the former pastor should have dropped out of the race.
Mr Romney was thwarted in West Virginia by tactical voting
Mr Romney, she insisted, was the only true conservative and Mr Huckabee was simply helping Mr McCain by splitting the conservative vote.
Mr Huckabee certainly benefited in West Virginia, where McCain supporters voted for him in order to prevent a win for Mr Romney.
Her friend Sandra said that if Mitt Romney lost the nomination she would prefer to vote for Hillary Clinton in the presidential election (if the New York senator clinched the Democratic nomination) than for another Republican.
Two big screens in the room have been showing live coverage of the election results, but when Mr Huckabee popped up from Arkansas, organisers at the HQ pumped up the music to drown out his voice.
One of the songs playing was Good Vibrations by the Beach Boys, but vibrations here in the Romney HQ did not feel that good.
'Not done yet'
Surrounded by his wife and five sons, Mr Romney came on stage as the crowds cheered wildly for the first time.
"My wife Ann told me tonight, that the only thing that is clear, is that nothing is clear," he started by saying.
"Well, she's wrong: one thing is clear, that this campaign is going, it is not all done."
He said it was still hard to tell how many delegates he had picked up in the different states but that the counting would continue till the early hours of the night.
He came in second in several states like Delaware and Illinois, where he will therefore pick up a proportional number of delegates.