WASHINGTON — The Supreme Court on Monday reaffirmed and strengthened constitutional protections for abortion rights, striking down parts of a restrictive Texas law that could have drastically reduced the number of abortion clinics in the state, leaving them only in the largest metropolitan areas.

The 5-to-3 decision was the court’s most sweeping statement on abortion since Planned Parenthood v. Casey in 1992, which reaffirmed the constitutional right to abortion established in 1973 in Roe v. Wade. It found that Texas’ restrictions — requiring doctors to have admitting privileges at nearby hospitals and clinics to meet the standards of ambulatory surgical centers — violated Casey’s prohibition on placing an “undue burden” on the ability to obtain an abortion.

If Casey limited the right established in Roe, allowing states to regulate abortion in ways Roe had barred, Monday’s decision effectively expanded that right. It means that similar requirements in other states are most likely also unconstitutional, and it imperils many other kinds of restrictions on abortion. It is also sure to energize anti-abortion forces and make abortion a central issue in the presidential campaign.

The decision concerned two parts of a law that imposed strict requirements on abortion providers in Texas signed into law in July 2013 by Rick Perry, the governor at the time.