Rick Perry has signed the Susan B. Anthony List pro-life pledge. Provisions of the pledge include only appointing pro-lifers to cabinet and executive branch positions, ending taxpayer funding of abortion, and fighting for legislation that would ban abortions on unborn children developed enough to be capable of feeling pain.
Michele Bachmann, Ron Paul, Newt Gingrich, Rick Santorum, and Thad McCotter have all signed the pledge. Mitt Romney and Herman Cain have not, for reasons cited here and here. Jon Huntsman has also not signed the pledge, but had previously announced he would sign no pledges during the election.