Sen. Dianne Feinstein — who has taken on the gun industry, the CIA and civil-liberties advocates in her own party during her long tenure in the Senate — will lead Democrats’ scrutiny of President-elect Donald Trump’s Supreme Court nominees for at least the next two years.

Feinstein (D-Calif.) was named ranking member of the Senate Judiciary Committee by incoming Senate Minority Leader Charles E. Schumer (D-N.Y.) on Wednesday, and she immediately made clear in a statement that Trump’s judicial nominations will go under a microscope.

“After the unprecedented and disrespectful treatment of Merrick Garland — a moderate judge who should have been quickly confirmed — the committee will pay very close attention to proposed nominees to ensure the fundamental constitutional rights of Americans are protected,” Feinstein said in a statement.

President Obama nominated Garland, a U.S. Court of Appeals judge, to fill the vacancy created when Associate Justice Antonin Scalia died in February. But Senate Republicans did not act on the nomination, betting that the next president would be a Republican who would nominate a conservative in Scalia’s mold.

With Trump’s election, the bet paid off.

Now Democrats have to determine how to handle Trump’s nominee, which is almost certain to be among the top items on his presidential agenda. While Democrats opted to change Senate rules in 2013 to allow a simple-majority vote on executive appointments and lower-court judges, Supreme Court nominees remain subject to the filibuster, requiring 60 votes to clear.

Feinstein takes over as ranking member from Sen. Patrick J. Leahy (D-Vt.), who opted to assume the top Democratic slot on the Senate Appropriations Committee. She was the first woman to serve on the Senate Judiciary Committee and is now the first woman to serve as chairman or ranking member of the panel, a premier role for any senator due to the high profile of Supreme Court confirmation hearings.

“When President-elect Trump is willing to support responsible policies and nominees, I’ll hear him out, but this committee has a vital role to protect the Constitution and scrutinize policies, senior officials and judges very carefully, and that’s what we intend to do,” she said in the statement. “We simply won’t stand aside and watch the tremendous successes achieved over the past eight years be swept away or allow our nation’s most vulnerable populations to be targeted.”

Feinstein is a veteran of tough policy fights on Capitol Hill, starting with her successful fight early in her tenure to impose a federal assault weapons ban. Since 2009, she has served as the chairman or vice chairman of the Senate Select Committee on Intelligence, which has placed her at the center of vital national security debates.

She launched a major review of the CIA’s use of torture during the George W. Bush administration, a move that led to serious clashes with the agency brass and ultimately led to the issuance of a 6,000-page report that unearthed new information about the extent of the torture and concluded that it did not meaningfully improve national security.

Feinstein, however, has clashed with civil libertarians and digital security activists due to her push for “back doors” in computer encryption alongside Sen. Richard Burr (R-N.C.), her Republican counterpart atop the Intelligence panel, as well as for her sharp criticism of Edward Snowden, the former National Security Agency contractor who disclosed major U.S. national security secrets.

Taking over for Feinstein as vice chairman of the Intelligence Committee will be Sen. Mark R. Warner (D-Va.), who has taken a more careful approach on digital encryption. He has called for the creation of a bipartisan commission to study the intersection of encryption and national security and recommend possible legislation.

Feinstein, 83, has yet to indicate whether she intends to seek a fifth Senate term in 2018. Her fellow senator from California, Barbara Boxer, also elected in 1992, did not seek reelection this year.