Thomas’s concurring opinion raises questions about what rights might be next.

Justice Clarence Thomas, in his concurring opinion overturning Roe v. Wade, laid out a vision that prompted concerns about what other rights could disappear: The same rationale that the Supreme Court used to declare there was no right to abortion, he said, should also be used to overturn cases establishing rights to contraception, same-sex consensual relations and same-sex marriage.

In the majority opinion written by Justice Samuel A. Alito, the court said that nothing in its decision “should be understood to cast doubt on precedents that do not concern abortion.” Justice Thomas said he agreed with that.

However, he noted that in its rationale, the court’s majority found that a right to abortion was not a form of “liberty” protected by the due process clause of the 14th Amendment to the Constitution — as the court had said in Roe.

Then, he took aim at three other landmark cases that relied on that same legal reasoning: Griswold v. Connecticut, a 1965 decision that declared married couples had a right to contraception; Lawrence v. Texas, a 2003 case invalidating sodomy laws and making same-sex sexual activity legal across the country; and Obergefell v. Hodges, the 2015 case establishing the right of gay couples to marry.

Justice Thomas wrote that the court “should reconsider” all three decisions, saying it had a duty to “correct the error” established in those precedents. Then, he said, after “overruling these demonstrably erroneous decisions, the question would remain whether other constitutional provisions” protected the rights they established.

This kind of language is just what advocates for reproductive rights and for L.G.B.T.Q. rights have been fearing. Defenders of the right to abortion have repeatedly warned that if Roe fell, the right to contraception and same-sex marriage would be next.

Abortion opponents, who fought hard to overturn Roe, have insisted they have no interest in trying to undo the right to contraception.

But already, states like Missouri are trying to restrict access to contraception by banning public funding for certain methods: intrauterine devices and the so-called morning after pill. And some Republicans, notably Senator Marsha Blackburn of Tennessee, have said that the Griswold case was wrongly decided. Earlier this year, Ms. Blackburn called Griswold “constitutionally unsound.”

Lawrence O. Gostin, a professor at Georgetown University Law School who specializes in public health law, said it would be “easy to dismiss Thomas as a lone wolf” and to do so would be a mistake. Now that the majority on the court has destroyed the foundation on which Roe was built, he said, “the other rights may well come crumbling after.”

Mr. Gostin cited another contentious legal area — gun rights — as an example. In ruling that the Second Amendment applies to individuals, he said, the court overturned a longstanding precedent.

At the time, he said, Justice Antonin Scalia said the decision would not affect other gun safety regulations. But “that promise didn’t last,” he said, noting that on Thursday, the court issued a major decision expanding gun rights