Democratic lawmakers plan to introduce legislation on Thursday that would add four seats to the Supreme Court, an initiative that has slim hopes of passage but reflects progressives’ impatience with President Biden’s cautious approach toward overhauling a court that turned to the right during the Trump administration.

Last week, Mr. Biden signed an executive order establishing a 36-member commission to report back within six months on possible changes to the Supreme Court’s membership, jurisdiction and lifetime terms. Mr. Biden appointed former Obama White House Counsel Bob Bauer and Yale law professor Cristina Rodriguez as co-chairmen of the commission; other members include many widely respected scholars, including some noted conservatives.

“We need more than a commission to restore integrity to the court,” said Sen. Ed Markey of Massachusetts, who is co-sponsoring the legislation with the House Judiciary Committee chairman, Rep. Jerrold Nadler of New York, and Reps. Hank Johnson of Georgia and Mondaire Jones of New York.

The White House didn’t immediately respond to a request for comment. The Supreme Court declined to comment.