Draft Opinion Overturning Roe Raises a Question: Are More Precedents Next?

Judge Alito dismissed that idea as “squarely foreclosed by our precedents” — citing a 1974 case about whether pregnancies must be covered by a state-run temporary employment disability insurance program and a 1993 case about anti-abortion protesters, and swiftly moving on.

The Roberts court era began in 2005, when Chief Justice Rehnquist died and President George W. Bush appointed John G. Roberts Jr. as his successor.

Later that year, Mr. Bush nominated his White House lawyer, Harriet Miers, to fill the vacancy created by the retirement of Justice Sandra Day O’Connor. But conservatives balked because she had no paper trail showing engagement with their ideology. Mr. Bush pulled her nomination and put forward Mr. Alito instead, beginning a rightward shift.

Overall, the Roberts court has not been unusually prone to overturning precedents, according to data compiled by Adam Feldman, a Supreme Court scholar and creator of the Empirical SCOTUS blog.

From 2005 through last term, the Roberts court has overturned precedents in about 1.47 cases per term, the fewest of any chief justice since World War II, Mr. Feldman’s data showed. Measured another way, the court has overturned precedents in 2.27 percent of the cases it has heard, a slightly lower rate than predecessors dating back to the Warren Court of the 1950s and 1960s.

But in recent years, the makeup of the court has changed drastically. Mr. Trump replaced a moderate conservative justice, Anthony Kennedy, and a liberal one, Ruth Bader Ginsburg, with justices who are considered much likelier to vote in a consistently conservative direction, Brett Kavanaugh and Amy Coney Barrett.

Along with Justice Alito, Neil M. Gorsuch, and Clarence Thomas, there is now a conservative supermajority on the court. And its ideologically median justice — who in close cases determines the majority — has moved from Justice Kennedy or Chief Justice Roberts to Justice Kavanaugh or Justice Barrett, legal scholars say, making it much likelier to issue conservative rulings.