“ Whether the Supreme Court of Puerto Rico would give the same broad sweep to 'just cause' as did the Court of Appeals is something we do not know. It is conceivable that 'just cause' might be judicially confined to a more narrow ambit which would avoid all constitutional questions. We therefore reverse and direct the Court of Appeals to remand the cases to the District Court with instructions to hold its hand until the Puerto Rican Supreme Court has authoritatively ruled on the local law question [4] in light of the federal claims. ”

“ II, § 7, of the Constitution of Puerto Rico provides that ' (n) o person shall be deprived of his liberty or property without due process of law,' 'life' being excluded because § 7 abolishes the death penalty. ”