Roberts, who dissented in the 2016 case, noted the Supreme Court's precedent in his concurring opinion: "The Louisiana law imposes a burden on access to abortion just as severe as that imposed by the Texas law, for the same reasons".
If the circumstances sound at all familiar, it's not your imagination. In 2016, the Supreme Court struck down a near identical law in Texas.
The Louisiana law "would drastically reduce the number and geographic distribution of abortion providers, making it impossible for many women to obtain a safe, legal abortion in the state", the ruling said.
A centrepiece of Trump's promises to his supporters was to turn the court rightward with the appointments of Neil Gorsuch and Brett Kavanaugh to the bench.
In a 5-4 decision, the court found unconstitutional a Louisiana law that requires doctors performing abortions to have admitting privileges at nearby hospitals. The result in this case is controlled by our decision four years ago invalidating a almost identical Texas law.
Wimes' decision in February 2019 rejected Planned Parenthood's argument that the law constituted an "undue burden" on women's constitutional right to an abortion.
Both sides saw the Louisiana case as a test of the court's view of abortion as a constitutional right.
In other words, Roberts showed respect for a four-year-old precedent - even though he disagreed with it at the time.
In his decision, Roberts indicated he sided with liberal justices exclusively out of respect to court precedent.
I'll look forward to seeing Maine's senior senator say today that she's "concerned" about Kavanaugh doing the opposite of what he promised to do.
The U.S. Supreme Court's ruling on Monday striking down a Louisiana abortion restriction means similar provisions in Missouri and Kansas are no longer enforceable. It followed by only two weeks a watershed, 6-3 decision in which the high court supported gay and transgender rights by ruling longstanding, non-discrimination protections in federal workplace law cover "sexual orientation" and "gender identity".
Since Kavanaugh joined the court last October, it has sent mixed signals on abortion.
Justice Stephen G. Breyer wrote the majority opinion in the Louisiana case, joined by Justices Ruth Bader Ginsburg, Elena Kagan and Sonia Sotomayor. In place of the "undue burden" rule regarding health and safety requirements, the Supreme Court should use a standard from a 1997 opinion that calls for "ordinary rational basis review", they said in the brief.