Judge Neil Gorsuch, President Donald Trump’s nominee for the Supreme Court, told senators during his second day of confirmation hearings Tuesday that he could not forecast how he would decide cases involving abortion.

Sen. Dianne Feinstein, D-Calif., asked Gorsuch, “Do you view Roe as having superprecedent?”

The Supreme Court’s 7-2 decision in Roe v. Wade on Jan. 22, 1973, legalized abortion across the nation.

Gorsuch, testifying before the Senate Judiciary Committee, acknowledged that lower courts have defended the decision, but said he is not able to predetermine how he would rule in similar cases.

“Well, Senator … [it is] a superprecedent,” he said to Feinstein. “It has been reaffirmed many times, I can say that.”

Superprecedent, a term that originated in 1976, refers to a legal precedent “so effective in defining the requirements of the law that it prevents legal disputes from arising in the first place, or, if they do arise, induces them to be settled without litigation,” according to the George Mason Law Review.

Sen. Chuck Grassley, R-Iowa, chairman of the Senate Judiciary Committee, earlier asked Gorsuch whether the Supreme Court correctly decided Roe v. Wade.

Gorsuch replied that while judges should respect past precedent, that does not give him the freedom to project future decisions.

“I would tell you that Roe v. Wade, decided in 1973, is precedent of the United States Supreme Court,” Gorsuch said. “It has been reaffirmed … So a good judge will consider as precedent of the United States Supreme Court worthy as treatment of precedent like any other.”

Precedent is important, he said, because it “adds to the determinacy of law.”

Hinting how he might judge, Gorsuch said, would be stripping his profession of its integrity:

If it looks like I’m giving hints or previews or intimations about how I might rule, I think that is the beginning of the end of the independent judiciary. If judges have to make effectively campaign promises … Respectfully, Senator, I have not done that in this process, and I’m not about to start.

Sen. Lindsey Graham, R-S.C., asked Gorsuch how he would have responded if Trump, in his interview of Gorsuch, had asked him to help overturn Roe v. Wade.

“Senator, I would have walked out the door,” Gorsuch said.

Gorsuch was expected to continue answering questions from the Judiciary Committee through Tuesday and Wednesday.