During the stem cell debate, Romney says, he had an epiphany on abortion. As recently as 2002, Romney had called his support for abortion rights "unequivocal." But in May 2005, he told USA Today that he was "in a different place." Two months later, he began saying that Roe v. Wade, the 1973 Supreme Court decision protecting abortion rights, had cheapened life. He vetoed a bill promoting emergency contraception, which he had supported as a candidate.

"Changing my position was in line with an ongoing struggle that anyone has that is opposed to abortion personally, vehemently opposed to it, and yet says, 'Well, I'll let other people make that decision,"' Romney said. "And you say to yourself, but if you believe that you're taking innocent life, it's hard to justify letting other people make that decision."

Romney also implemented abstinence-only sex education in public schools, reversing another campaign position. Moreover, the candidate who'd been endorsed in 2002 by the Log Cabin Republicans, a gay group, for his message of tolerance and embrace of some domestic partner benefits, became a crusader against gay marriage.

After the Supreme Judicial Court legalized same-sex marriage in Massachusetts in November 2003, he testified on behalf of a federal gay-marriage ban before a US Senate committee, lobbied lawmakers on a proposed state ban, and was the featured speaker at a nationally broadcast anti-gay marriage rally last fall at a Boston church.

"For four years, Governor Romney has been right there beside us, providing leadership on key issues — whether it was politically expedient to do so or not," Kris Mineau, president of the Massachusetts Family Institute, wrote in a letter to conservatives early this year.

But where conservatives saw leadership, skeptics, even some Republicans, saw opportunism, believing Romney's political agenda contributed to the further decline of the GOP in Massachusetts, which saw its numbers dwindle to historic lows of 19 House members and five senators, out of the 200-member Legislature.

"It's almost as though he had his eye on higher office very early into his governorship. I think it ended up hurting his performance as governor, and the fortunes of the party in general," said Senate minority leader Richard R. Tisei, of Wakefield, a supporter of Rudy Giuliani in the presidential race and one of four Republican state legislators who are not backing Romney.

Allies drift away

Early in Romney's term, Senate minority leader Richard R. Tisei and other Republicans generally stood by their governor. But later, they began to desert him with regularity, as Romney's vetoes seemed aimed in part at impressing Republicans outside the state.