Bush was asked in a brief exchange with reporters to clarify his comments Thursday in which he had said the Roe vs. Wade decision in 1973 "was a stretch."

Asked today if he felt the decision should be overturned, Bush said, "I felt like it was a case where the court took the place of what the legislatures should do in America." Asked what he thought the state legislatures should do, he said, "It should be up to each legislature."

Steve Forbes, Bush's chief Republican rival in the Iowa caucuses, said the Texas governor was waffling on the subject by not pushing for action to stop abortion.

"I think it's very clear the Republican Party should not nominate a candidate who is not going to publicly, overtly and openly seek to overturn Roe vs. Wade," Forbes said in a telephone interview between campaign stops. "If he's trying to hedge and use verbal gymnastics on that, it's not going to work."

Abortion is a critical issue in the caucuses in Iowa where social conservatives will make up a large chunk of the vote Monday night.

Bush has been fielding questions on the topic for two days, criticizing the Supreme Court ruling without directly saying that Roe vs. Wade should be overturned.

He has talked about abortion only when asked by reporters, preferring to avoid a topic that could alienate many swing voters who will be key in the general election.

His approach was clear today when he was asked whether the decision should be overturned and he kept giving the same response. "That's the case where the court stepped across its bounds and usurped the rights of the legislatures," he said. "It's a case of overstepping its bounds."

Bush spokeswoman Karen Hughes said the remarks were consistent with his longstated view that the Supreme Court should strictly interpret the Constitution in all cases including abortion and such issues should be left to state legislatures and Congress to decide.

Bush's ultimate goal is a constitutional amendment banning abortion -- except in cases of rape, incest or danger to the mother's life -- which state legislatures as well as Congress would have to approve. Bush has said the country is not ready to pass such a sweeping amendment.

On Thursday, Bush said that if the daughter of a friend or relative were raped and asked him about abortion, he would advise that "it's up to her" whether to end the pregnancy.

He also said the Roe vs. Wade decision "was a reach," and that he "would not be inclined to accept" government approval of abortion-inducing medicines such as the French pill RU-486.

"It's abortion," Bush told reporters during a news conference at Central College where he was bombarded by abortion questions and, later, criticism from his rivals.

Forbes told reporters Thursday after touring an abortion-counseling center that the procedure can leave women emotionally scarred, and he accused Bush of not doing enough to oppose it.

"What all this underscores is that it's not enough just to say one is pro-life," Forbes told reporters at the Aid to Women center in Cedar Rapids. "You have to find ways to move people, even if it's just step-by-step, toward your goal."

Rival Alan Keyes reacted with surprise to Bush's comments on Roe vs. Wade. "He's just realizing this? Oh my gosh," Keyes said.

"If he has reached this conclusion for the sake of political expediency, then I hope it's too late," Keyes said before an appearance in Mason City. "But if it reflects real conviction, then it's never too late to admit the truth."

With the Iowa caucuses on Monday, Bush is working to convert his lead in public opinion surveys into victory.

"It's one thing to have a nice lead in the polls. It's another thing to have a lead when they actually show up" at caucus sites, the Texas governor told reporters.

In a boost for Bush today, the 30-member Republican Governors Association endorsed his tax-cut plan -- a proposal that association chairman Ed Schafer of North Dakota said would allow "the hardworking men and women of this nation to keep more of the money they earn."

New Hampshire Sen. Judd Gregg also praises Bush's tax plan in a new ad the campaign began running on Boston and New Hampshire stations today. Gregg says in the ad, "Now some say Bush's plan to cut taxes is too much. They believe if you leave money in Washington, it will not be spent. We know better."

Forbes, Keyes and conservative activist Gary Bauer are trying to distinguish themselves from Bush in the eyes of conservative voters by elevating the abortion issue.

Moral issues have great sway over voters, particularly in the year after President Clinton's impeachment trial for his affair with a White House intern.

Hoping to tap into such sentiment, Forbes is running TV ads in the state featuring women who insist that fetuses are people deserving of the legal protections he advocates. Bauer and Keyes are also running abortion ads.

Associated Press writer Scott Lindlaw contributed to this report.