The White House is bracing for the Supreme Court to chip away at the landmark 1973 abortion case Roe v. Wade as the justices consider the constitutionality of a Mississippi law banning the termination of pregnancies after 15 weeks.

The majority’s inclination toward upholding the Mississippi law, evident during oral arguments Wednesday, has rattled advocates of legal abortion but has some Democrats believing it will boost the party in next year’s midterm elections.