It would be wonderful if the obligations clause automatically overturned the ban against gay marriage. Unfortunately, I don’t think it’s that cut-and-dried.

The obligations clause was originally put into the Constitution to address, specifically, economic contracts, particularly those related to debtors and the imprisonment of debtors, and also to address the handling of bills of attainder. In the early days of the nation, Justice Marshall applied the clause broadly in Supreme Court decisions to rein in states’ rights to address things like public land grants.

But today, the Supreme Court is mainly silent on the obligations clause, because the general consensus is that states have the right to regulate their own economic systems.

I don’t think this clause has ever been applied by any high court decision to private contracts, like a marriage contract. That’s not saying it couldn’t be, because the law is a fluid thing, but given the history of how it’s been applied, it seems unlikely.

where it says:

or law impairing the obligation of contracts,