LITTLE ROCK — Proposed abortion restrictions currently moving through the Legislature likely would run afoul of the Constitution and U.S. Supreme Court precedent if they become law, according to a law professor at the University of Arkansas at Little Rock.

Theresa Beiner disputed testimony by the bills’ supporters before legislative committee’s last week that the nation’s highest court has cleared the way for banning an abortion after as few as 12 weeks of pregnancy.

Opponents insisted in testimony before lawmakers the measures would not pass constitutional muster because the Supreme Court has ruled states cannot ban abortions before a fetus becomes viable, or able to live outside the womb.

Addressing the House Public Health, Welfare and Labor Committee on Thursday, Sen. Jason Rapert, R-Conway, asserted that his Senate Bill 134 is constitutional. As amended last week, the bill would require a woman seeking an abortion at 12 weeks or more into a pregnancy to undergo a test for a fetal heartbeat, and if a heartbeat is detected an abortion could not be performed unless the mother’s life is in danger or the pregnancy is the result of rape or incest.

An earlier version of the bill did not contain the 12-week limit and therefore would have banned abortions as early as five or six weeks.

Doctors generally consider a fetus to be viable at 23 or 24 weeks. No state currently bans abortions as early as 12 weeks, but Rapert told the House committee that if Arkansas were to adopt such a ban, it would withstand a court challenge.

"The U.S. Supreme Court has allowed states to prohibit abortions before viability," Rapert told the panel.

He said his bill was "vetted by legal scholars" but did not name them.

Beiner, who teaches constitutional law at UALR, said the court has never issued such a ruling.

"This all comes from Planned Parenthood v. Casey, where viability became the touchstone of when you could begin to prohibit abortions," she said. "That doesn’t mean you can’t regulate abortions before viability, but it’s going to be regulation, it’s not going to be prohibition."

In that 1992 decision, the high court said a woman has a right "to choose to have an abortion before fetal viability and to obtain it without undue interference from the state, whose pre-viability interests are not strong enough to support an abortion prohibition or the imposition of substantial obstacles to the woman’s effective right to elect the procedure."

Beiner said states can impose limited restrictions on abortions before viability, but the high court has established that states cannot impose an undue burden on a woman’s right to an abortion before viability.

"An entire prohibition is an undue burden, by definition," she said.

Rapert has argued that in a more recent U.S. Supreme Court ruling, 2007’s Gonzales v. Carhart, the high court upheld a ban on so-called partial birth abortion regardless of whether they are performed before or after viability.

Beiner called the argument is "sort of specious."

"Those are later-term abortions, when that procedure is used. Earlier abortions don’t use what is termed partial-birth," she said.

Gov. Mike Beebe has said he believes Rapert’s bill is unconstitutional but has not said whether he would veto it. A veto could be overridden with a 51 percent majority vote in the House and Senate.

Meanwhile, House Bill 1037 by Rep. Andy Mayberry, R-Hensley, would ban abortions at 20 weeks — the point at which the bill contends a fetus can feel pain — except to save the mother from death or severe physical impairment. It contains no exception for rape or incest.

Mayberry has noted that a federal judge has upheld a 20-week ban on abortions in Arizona. The case is on appeal.

"It’s before the (U.S. Circuit) Court of Appeals, No. 1, and No. 2, the Supreme Court hasn’t changed the standard yet," Beiner said. "It could well be this judge is going to get overturned. It’s a lower-court decision; it’s not even binding in this jurisdiction."

Asked if there is any reason for supporters of the bills to hope that the Supreme Court will change its standard in the near future, Beiner said there doesn’t appear to be.

"They had an opportunity in the Carhart case, and they didn’t. They could have overturned Roe v. Wade and prohibited abortion across the board in that case," she said. "I didn’t happen, so my guess would be that they’re not going to overturn the right to terminate a pregnancy pre-viability."

The court is no more conservative now that it was in 2007, Beiner said.

The American Civil Liberties Union and Planned Parenthood have said they will sue the state if the bills become law.

The Christian conservative Family Council supports both bills. Jerry Cox, the group’s president, said Friday the group has been getting legal opinions from lawyers and said he hoped to have them by Monday. He declined to name the lawyers.

Rapert did not immediately return a phone call seeking comment Friday.

Mayberry’s bill is part of the legislative package of Arkansas Right to Life, which has not taken a position on Rapert’s bill. Rose Mimms, the group’s executive director, on Friday referred questions about the constitutionality of its bill to National Right to Life Committee attorney Marcy Balch of Washington, D.C., who did not immediately return a call seeking comment.

If either or both of the bills were to become law and be struck down, it would not be the first time an Arkansas abortion law has been overturned. In 1999, the 8th U.S. Circuit Court of Appeals upheld a federal judge’s ruling overturning an Arkansas law banning so-called partial-birth abortions, finding that the law was vague, overly broad and could have a chilling effect on other procedures.

A ban on the procedure that the Legislature passed in 2009 is still on the books.

Rapert’s bill previously passed the Senate and cleared the House Public Health Committee on Thursday. It is expected to be on the House floor sometime this week.

Mayberry’s bill previously passed the House and is expected to be taken up by the Senate Public Health Committee on Wednesday.