OSCEOLA, Iowa -- Republican presidential candidate Rick Perry on Tuesday said he had strengthened his opposition to abortion and now opposes the procedure even in the case of rape, incest or when the woman's life would be at risk."You're seeing a transformation," Perry said while describing his views.Perry said the change followed a meeting with a woman whose mother was raped and whose story was part of an abortion documentary screened by former Arkansas Gov. Mike Huckabee. The encounter "started giving some thought to the issue of rape and incest," Perry said.Perry's shift comes just a week ahead of Iowa's Jan. 3 caucuses that launch the Republican nominating contest. Social conservatives hold great sway here and gave Huckabee an upset win four years ago.Perry, whose polling has slid in recent months, is working to win over hold-out caucus-goers and cultural conservatives. Time is running short, however, and he is trying to recapture the enthusiasm that greeted his entrance to the race in August only to see his luster fade after campaign fumbles and weak debate performances.He also faced challenges even getting on primary ballots. Late Tuesday, his campaign announced a lawsuit challenging Virginia's ballot rules.Perry - as well as rival Newt Gingrich - came up short of the signatures required to get on the delegate-rich state's March 6 primary. Only former Massachusetts Gov. Mitt Romney and Rep. Ron Paul of Texas met the requirement."Virginia ballot access rules are among the most onerous and are particularly problematic in a multi-candidate election," Perry campaign spokesman Ray Sullivan said in a statement announcing the lawsuit.The state requires a total of 10,000 signatures, with 400 from each of its 11 congressional districts.Despite the potential setback in Virginia, Perry returned to hand-to-hand campaigning, his strength, and is blanketing Iowa airwaves with ads promoting his biography and his record.Campaigning as a hard-talking outsider, Perry planned to rumble through Iowa on a bus tour, meeting with supporters in coffee shops and diners non-stop ahead of the caucuses. As he ended the day, a pastor in the audience of a town hall-style meeting questioned him about a recent endorsement of a pledge that opposes abortion in all cases.Perry signed the Personhood USA pledge, which states "abortion and the intentional killing of an innocent human being are always wrong and should be prohibited." Gingrich, Rep. Michele Bachmann of Minnesota and former Sen. Rick Santorum of Pennsylvania also signed the pledge.Paul signed the pledge but with a footnote to emphasize his libertarian beliefs.Previously, Perry said he would allow abortion in cases of rape, incest or when the mother's life is at risk. He said he changed that view earlier this month after the Huckabee film screening."When the lady who was in it was looking me in the eye and saying, 'You need to think this through,' she said, 'I am the product of a rape' and she said 'my life has worth,'" Perry said. "It was a powerful moment for me."