The Supreme Court on Monday struck down a Louisiana law that could have left the state with a single abortion clinic. It was a setback for conservatives in the first major ruling on abortion since two Trump appointees joined the bench. We examine the implications for future challenges, and why — for the third time in two weeks — Chief Justice John G. Roberts Jr. sided with his four more liberal colleagues.

Guest: Adam Liptak, who covers the Supreme Court for The Times.

For more information on today’s episode, visit nytimes.com/thedaily

Background reading:

• Chief Justice Roberts also voted with the court’s liberal wing in rulings on job discrimination against L.G.B.T.Q. workers and on a program protecting young immigrants.
• The ruling on Monday stalled anti-abortion momentum for now, but the movement has a long pipeline of new cases.
• Justice Stephen G. Breyer wrote that the Louisiana law was “almost word-for-word identical” to a law from Texas, which the court struck down in 2016.