LINCOLN, NEB. - Mike Flood, the 35-year-old speaker of Nebraska's legislature, had a problem: He wanted to stop the state's well-known abortion provider from offering late-term abortions.

A long line of Supreme Court precedents seemed to stand in his way. But Flood believes that a 2007 decision offers hope for him and other state legislators looking for ways to restrict abortion.

Using that decision as a road map, this spring Flood wrote and won passage of legislation that bans abortions after 20 weeks. Introducing into law the concept of "fetal pain," it marked the first time that a state has outlawed the procedure so early in a pregnancy without an exception for the health of the woman.

The law shut down LeRoy Carhart, the provider who had planned to expand his practice outside Omaha and provide late-term abortions to women across the Midwest.

The importance of Flood's bill is likely to be felt far beyond Nebraska. Abortion opponents call it model legislation for other states and say it could provide a direct challenge to Supreme Court precedents that restrict government's ability to prohibit abortion before a fetus can survive outside the womb. (It also prompted Carhart to shift his practice east, and he has since opened a late-term practice in Germantown, outside Washington.)

Critics of abortion hail the law as the most prominent and promising outcome of the Supreme Court's 2007 decision, in which, coincidentally, Carhart was the lead plaintiff.

The 5 to 4 decision in Gonzales v. Carhart turned away Carhart's challenge to the federal ban on "partial birth" abortion and appeared to mark a significant change in the high court's balancing of a woman's right with the government's interest.

The ruling was a key moment in the emerging identity of the court headed by Chief Justice John G. Roberts Jr., who marked his fifth anniversary on the court this fall.

Roberts and Justice Samuel A. Alito Jr., also nominated by President George W. Bush in 2005, have become part of a conservative majority willing to reconsider the court's position on social and political issues. Race, campaign finance and the ability of plaintiffs to sue are some of the issues touched by the court's changing jurisprudence.

But since the Roe v. Wade decision in 1973, no social issue has been as entwined with the court than abortion, nor as dependent on its nuance and shifting views.

That's what made the 2007 decision so important to both sides of the issue.

"Many in the pro-life movement have become very pragmatic when it comes to the court: 'Can you count to five?' " said Mary Spaulding Balch, director of state legislation for the National Right to Life Committee. "With the Gonzales decision, we were happy to see that we could."