Correction Appended: Nov. 16, 2009

Republican congressional leaders have to be chuckling right now. In the end, all the tea-party town halls, Glenn Beck rallies and "death panel" rumors may have less of a hand in bringing down health care reform than an intraparty Democratic culture war.

Congressman Bart Stupak of Michigan, whose amendment restricting abortion coverage on all policies sold through the new insurance exchange paved the way for passage of health reform in the House of Representatives, vows that "there will be hell to pay" if his language gets stripped out of, or weakened in, the final legislation. Senate moderates like Ben Nelson and Kent Conrad have stopped short of demanding the exact Stupak language, but have warned that weak abortion restrictions could force them to vote no on health reform. Abortion-rights advocates, who are still stunned by the last-minute deal that House Speaker Nancy Pelosi made to allow a vote on Stupak's controversial measure, claim the provision will greatly limit the availability of abortions, especially for low-income women. They have dubbed it "the coat-hanger amendment."

Before the Nov. 7 House vote on health reform, the advocacy organization Health Care for America NOW! (HCAN) had lobbied vulnerable Democratic House members by promising to back them with ads if they supported health reform. In the wake of the vote, the group amended that pledge, saying it would not apply to those who helped pass health reform if they also voted for the Stupak amendment. NARAL Pro-Choice America president Nancy Keenan is publicly mulling going one step further and supporting primary challenges against Stupak-voting Democrats. "Nothing's off the table," she told Jill Lawrence at PoliticsDaily. "We're going to hold those accountable who voted against us."