WASHINGTON — Roe v. Wade has had a rough two weeks at the Supreme Court.

On Dec. 1, at arguments over its fate in a case from Mississippi, the five most conservative justices showed no interest in doing anything short of overruling it.

Then, on Friday, those same five justices allowed a Texas law that bans most abortions after six weeks to remain in place and seemed to shut down any effective way to challenge it in federal court. That law, which has been in place since Sept. 1, is flatly at odds with Roe, which established a constitutional right to abortion and prohibited states from banning the procedure before fetal viability, or around 23 weeks of pregnancy.

A decision in the Mississippi case is not expected until late June. If the court overrules Roe, an increasingly real possibility, it will have to explain why it is departing from the principle of stare decisis, which is legal Latin for “to stand by things decided.”