Senators on the Judiciary Committee that is holding confirmation hearings in January for Supreme Court Justice Samuel Alito are expected to ask many questions about his views on abortion.

Some of the questions may be about cases Alito reviewed as an appeals court judge, including the one Alito told Sen. Richard Durbin he spent more time considering than any other case in his career.

Click on the video box at the top of the story to watch a report by FOX News' Megyn Kendall.

Planned Parenthood vs. Casey was decided by the 3rd Circuit Court of Appeals in 1991. A group of abortion clinics sued Pennsylvania's former Gov. Robert P. Casey and others, which challenged a state law that restricted abortions.

The appeals court, which included Alito, reviewed the law using a standard set out by Supreme Court Justice Sandra Day O'Connor. They considered whether the restriction posed an "undue burden" on a woman seeking an abortion.

Under that restriction, the appeals court panel split over a section of the law that required married women seeking abortions to first inform their husbands. The two-judge majority, which did not include Alito, voted to overturn the law.

"The number of different situations in which women may reasonably fear dire consequences from notifying their husbands is potentially limitless. [As a result,] we hold that [this law] constitutes an undue burden on a woman's abortion decision," the judges wrote.

Alito dissented from the decision.

"The plaintiffs did not even roughly substantiate how many women might be inhibited from obtaining an abortion or otherwise harmed by [this law]. At best, the record shows that [the law] would inhibit abortions 'to some degree'. ... Consequently, the plaintiffs failed to prove ... an undue burden," Alito wrote.

Former Alito colleague Michael Carvin defended Alito's decision.

"He took Justice O'Connor's analysis, applied it in a way that said, at least in a facial challenge, 'I don't think women face an undue burden if they have to tell their husbands that they're going to have an abortion.' Remember, the husband got no veto power, there was no question of consent, it was just notify him," Carvin said.

The Supreme Court later rejected Alito's position, which has some abortion rights groups claiming the court justice nominee is an extremist.

"The Supreme Court disagreed with him. So you have the justices saying, 'No, this is too much, this affects women's lives far too much.' Then he was out of the mainstream, and he continues to be out of the mainstream," said Nancy Keenan, president of NARAL Pro-Choice America.

But Carvin defended Alito, saying the charge is baseless and pointed to other cases in which Alito voted to strike down abortion restrictions.

"Obviously, if he was driven by his personal views on abortion, which whatever they may be and I have no idea what they are, he couldn't have decided the way he did because his results point in two different directions," Carvin said.