Texas Gov. Rick Perry’s “transformation” on abortion rights is the starkest rightward shift among the Republican candidates vying for Iowa’s social conservatives, but he’s hardly alone in targeting abortion rights as part of his campaign strategy.

Trailing in the polls behind conservative candidate Rick Santorum, Texas Perry told an Iowa pastor he’s now opposed to abortion even in cases of rape and incest.

{mosads}Four of the remaining GOP presidential hopefuls – Santorum, Newt Gingrich, Rep. Ron Paul (Texas) and Rep. Michele Bachmann (Minn.) – have joined Perry in signing the Susan B. Anthony List’s “pro-life pledge.” The pledge binds its signers to nominate conservatives to the bench and to head federal agencies; to end taxpayer funding for abortion and defund Planned Parenthood; and to champion legislation outlawing abortions after 20 weeks.

The same five candidates have also embraced a Personhood USA pledge to support legislation and constitutional amendments recognizing the unborn as persons with legal rights. Critics worry such measures could outlaw birth control and fertilization; they have been rejected everywhere they’ve been on the ballot, including in Mississippi, a state with a heavily Republican voting history.

Gingrich has gone one further, promising during an appearance at an Iowa tele-townhall Tuesday to rein in judges and champion anti-abortion rights legislation that would not be appealable to the courts. 

Perry for his part told the town hall’s host, Steve Deace, that “obviously, you would enforce the right to life” rather than a court decision striking it down. (Deace endorsed Gingrich on Friday.)

The candidates’ criticism of the courts plays well with some Christian conservatives who have long been dismayed by the 1973 Roe v. Wade case recognizing a federal right to abortion. Some conservatives and legal scholars, however, question the wisdom and legality of curtailing the courts’ powers.

The renewed focus on abortion might not help the more conservative candidates.

Just days before the Jan. 3 caucuses, the two candidates leading the pack in Iowa are both viewed with suspicion by social conservatives.

Former Massachusetts Gov. Mitt Romney supported abortion rights when he ran for the Massachusetts Senate seat in 1994 and again when he won the governorship in 2002. Since 2004, he has been opposed to abortion rights but has declined to sign onto the Susan B. Anthony List or the Personhood USA pledges.

Paul remains wary of having federal legislation override states’ rights, earning him a rebuke from the Personhood USA movement.

“If Rep. Ron Paul believes that the preborn are persons under the law, why wouldn’t they be protected under the 14th amendment?” Personhood USA legal analyst Gualberto Garcia Jones said in a statement Monday. “Rep. Paul’s vague statement on the duty of the federal government to ‘protect rights’ is without effect if there is no mechanism for guaranteeing those protections.”