So how did Mitt Romney decide to exit the race? Eric Fehrnstrom, the former Massachusetts governor’s traveling press secretary, said the first clue came at a meeting of about 10 senior staffers at headquarters in Boston yesterday. At that session, Fehrnstrom says, Romney indicated that he “didn’t want to do anything that would hurt the party or hurt the nation.” That comment gave Fehrnstrom, a longtime Romney aide, an inkling that something was up. But Romney went on to attend a meeting of all staff at headquarters, at which he was “cheered and encouraged by his campaign workers and volunteers to go forward.” At about 3 p.m. yesterday, the New York Times reported that Romney strategists said the candidate intended to stay in the race, indicating they were discussing the possibility of winning over unbound delegates as a way of cobbling together a win. Romney headed home to Belmont late yesterday afternoon, to write up the speech he would give Thursday at the Conservative Political Action Committee’s winter meeting. As he wrote, the address “turned into a farewell speech,” Fehrnstrom said.

As always with Romney, family was key. He consulted with his five sons and wife, Ann, before making the decision. Ann and son Tagg were both present at yesterday’s senior staff session. Word spread among his top aides, as they swapped copies of the speech. Fehrnstrom himself was taking in a Celtics game when he learned his boss was getting out.

Following the CPAC speech, Romney immediately got on the phone with his national finance co-chairs and later Thursday afternoon will head up to Capitol Hill and meet with congressional supporters (who learned of his decision along with the CPAC audience).

Meanwhile, McCain was preparing for his own talk to the CPAC crowd. At about 2 p.m., he entered the lobby of DC’s Omni Shoreham to the cheers of some 200 screaming, sign-waving supporters-who presented a stark contrast to Romney’s faithful, who wandered dejectedly through the lobby. Alexandra Smith, an 18-year-old Catholic student, was typical of them. She said she began receiving texts about news reports about Romney’s decision a few minutes before the CPAC speech but didn’t know whether to believe them. But when Romney began talking and referred in his speech to this not being 1976, when Reagan went all the way to the convention, she said she knew. “I’ll sit home on Election Day,” she said. “There’s no conservative [left].”