Former Massachusetts Gov. Mitt Romney's (R) campaign honeymoon appears to have ended, as other candidates for the Republican presidential nomination begin voicing open criticism of him.

Romney, by virtue of his status as the putative front-runner in the race, is now facing increasingly vocal criticism from his competitors — criticism that had otherwise been muted or nonexistent so far in the campaign.


The attacks suggest that the campaign for the 2012 Republican nomination hasn't just begun, but has advanced to the point where candidates have started to throw elbows, jockeying for position with primary voters.

There was no better example of this inflection point than last week's criticism of Romney by former Minnesota Gov. Tim Pawlenty (R), who coined the term "ObamneyCare" to tie together President Obama's healthcare law, so detested by GOP primary voters, and the similar law Romney signed during his term as governor.

The flak Pawlenty caught for not having made that point directly when sharing a stage with Romney during last week's New Hampshire debate only underscores the pressure the campaigns are facing to throw punches.

"I think the main focus does need to be on President Obama and his failure as a president," Pawlenty said last week on Fox News. "But there's going to be some policy differences between the rest of us, and bringing those out in a respectful policy-based way, I think, is appropriate — particularly in the context of a debate."

The sniping between the campaigns that had persisted behind the scenes is now in the open; the candidates had largely avoided leveling direct criticism at one another, but that stage appears to have passed, especially as the field of contenders hardens.

The criticism leveled by candidates toward one another certainly won't be limited to Romney, but the former Massachusetts governor has borne the brunt of the attacks — a testament to other campaigns' efforts to gain traction against Romney, who leads most polls of Republican primary voters' choice in a nominee.

The Republican field piled on Romney over the weekend after he refused to sign a "Pro-Life Presidential Leadership Pledge" composed by the Susan B. Anthony List (SBA List), an anti-abortion-rights group.

Both Romney and Herman Cain declined to take the pledge, and Romney explained that while he considers himself an opponent of abortion rights, the SBA List's "well-meaning pledge is overly broad and would have unintended consequences."

That explanation didn't stop Romney's primary challengers from pouncing, though.

"It is distressing that Gov. Romney refuses to sign the SBA Pledge, even while claiming to be pro-life," said Alice Stewart, a spokeswoman for Rep. Michele BachmannMichele Marie BachmannEvangelicals shouldn't be defending Trump in tiff over editorial Mellman: The 'lane theory' is the wrong lane to be in White House backs Stephen Miller amid white nationalist allegations MORE's (R-Minn.) presidential campaign. "The excuses for not signing clearly continue the doubts about his leadership and commitment to ending the practice of abortion — particularly for a candidate who ran as pro-choice for the Senate and governorship of Massachusetts."

"This past Monday night at the Republican presidential debate, I was asked about Gov. Romney's pro-life conversion, and I gave him the benefit of the doubt. I apparently spoke too soon. It is incredibly disappointing that Gov. Romney chose not to defend those who cannot defend themselves," said former Sen. Rick Santorum (R-Pa.). Even after Romney's explanation, Santorum doubled down, suggesting that Romney's answer was insufficient.

And even Texas Gov. Rick Perry (R), who might make a late entry into the campaign, sent a shot across the bow of the other candidates during a speech this weekend before conservative activists.

"It saddens me, sometimes, when my fellow Republicans duck and cover in the face of pressure from the left,” Perry said at the Republican Leadership Conference. “We need to redouble our efforts to elect more conservative Republicans.”