Republican U.S. Sen. Josh Hawley is questioning the anti-abortion credentials of Trump appeals court nominee Neomi Rao, prompting other conservatives to come to her defense.

Hawley’s hesitation on Monday raises tension among some Republicans over her nomination to replace now-Supreme Court Justice Brett Kavanaugh on the U.S. Court of Appeals for the District of Columbia Circuit.

Hawley joins Joni Ernst of Iowa and at least one other Republican senator, who hasn’t been identified, raising questions publicly or privately in recent weeks over Rao.

The stakes are higher than usual as some believe the top Trump administration regulatory official could be a short-list candidate for the U.S. Supreme Court. A potential high court nomination is magnified here because the D.C. Circuit rarely handles abortion cases.

Writings, Due Process

The Senate Judiciary Committee has yet to vote on Rao’s nomination, but the Republican-led Senate is again ramping up consideration of President Donald Trump’s judicial appointments, a bright spot in an otherwise rocky relationship between the White House and Congress.

Hawley said that he was concerned that Rao’s academic writings may indicate a view about due process that he says could be used to protect rights not expressly listed in the Constitution, like abortion rights.

“I want to make sure that Neomi Rao is pro life, it’s as simple as that,” the Missouri lawmaker said in a radio interview.

“I haven’t made up my mind which way I’m going to vote on this nominee, but I want to be clear that I’m going to support only judges who respect life and who are going to give it as much protection as they can under current Supreme Court doctrine,” Hawley said.

Rao has written “some things in the past that suggest to me that she might be more of a judicial activist in this area and not somebody who respects life,” Hawley said in the interview with talk radio’s The Marc Cox Morning Show.

The first-term lawmaker, a former Missouri attorney general who clerked for U.S. Supreme Court Chief Justice John G. Roberts Jr., didn’t specify which writings bothered him. Rao described arguments supporting and opposing abortion based on concepts of dignity, in a 2011 law review article.

Conservatives and libertarians pushed back against Hawley.

Rao is committed to the U.S. Constitution and has been a “warrior” in “Trump’s fight against government overreach,” Carrie Severino of the Judicial Crisis Network, a vocal supporter of President Donald Trump’s judicial nominees, said.

The anti-abortion Faith and Freedom Coalition said it “strongly supports” Rao, in response to Hawley.

Ilya Shapiro of the libertarian Cato Institute also supported Rao, calling the doubts about her “ridiculous,” in a tweet.

“She’s one of the greatest minds on administrative law” of her generation, Shapiro said.

Robes vs. Capes

A former Senate staffer said criticism of Rao based on her personal views goes “against every originalist instinct.”

Even if Rao personally supports abortion rights, she has promised to put her views aside and interpret the law as written, the staffer said.

Conservatives and originalists should want judges who, as Justice Neil M. Gorsuch said, wear robes rather than capes, the staffer said.

Ernst said at Rao’s confirmation hearing that her college writings on rape gave her pause. Some of Ernst’s concerns, however, reportedly were allayed after she met with Rao.