“Did they rule that all States must ALLOW same-sex marriage or did they rule that all states must RECOGNIZE same-sex marriage.”
Both, in separate cases. The recognition issue should have been a slam-dunk 9-0 decision. My father’s first cousin got married without her parents knowledge or permission at the age of 17 when that was illegal in most states (although not where she got married). No state, however, ever would question the validity of her marriage. (She and her husband were married for 66 years, until her husband finally died in his late 80s.)
The allow issue should have been decided purely on equal protection grounds; there are many, many legal and financial benefits to marriage that were unavailable to same sex couples that were available to opposite sex couples. This could have been fixed by enacting civil union laws in every state, but the anti-gay crowd was every bit as opposed to that as to marriage. That strategy has proven disastrous.