Washington ? Thirty states are poised to make abortion illegal within a year if the Supreme Court reversed its 1973 ruling establishing a woman’s legal right to an abortion, an advocacy group said Tuesday.

The Center for Reproductive Rights said some states have old laws on the books that would be triggered by the overturning of the landmark Roe v. Wade decision. Others have language in their state constitutions or strongly anti-abortion legislatures that would act quickly if the federal protection for abortion was ended and the issue reverted to the states.

“The building blocks are already in place to recriminalize abortion,” said Nancy Northup, the center’s president.

The group’s report comes less than a month before the presidential election, which those on both sides of the abortion issue say will be critical in determining the future of the Roe decision.

Currently, it is believed that five of the nine justices support abortion rights, but that balance could be tipped if President Bush, in a second term, nominates a new justice who reflects his anti-abortion views. Democratic contender John Kerry is a strong supporter of abortion rights.

The center concluded that 21 states are at high risk, and nine states — including Kansas — are at middle risk, of banning abortion within a year of Roe being overturned. More than 70 million women of childbearing age would be affected, the center said.

Tony Perkins, president of the Family Research Council, a leading opponent of abortions, agreed that 30 states or more would move to restrict or curtail abortion if Roe was overturned. “The court is out of step with the rest of America,” he said. “I have no doubt that you would see a majority of the states take action to protect unborn children and their mothers.”