Now that SCOTUS has overturned VA's gay marriage ban, I think it's fairly safe to say that there aren't any gay marriage bans on the books in any state that could withstand a federal lawsuit.
Conservatives know this and are in full-blown panic mode throwing Jello at the wall indiscriminately and figuring maybe there's a small chance some will stick. At this rate, I'm waiting for a legislator in Oklahoma or Alabama to introduce a bill replicating Uganda's kill-the-gays law or Nigeria's mandatory jail time for gays.
SCOTUS hasn't overturned anything yet. A federal district court struck down Virginia's ban but stayed the decision pending appeal. It remains to be seen who will have standing to appeal. The two county clerks who defended it in trial might. If nobody has standing, then gay marriages will begin in Virginia very soon. That's a huge victory for sure, but we're still two years away from the big SCOTUS decision.
But your general point is right. The state-level bans are dropping like flies in the district courts, and it's only a matter of time before we get some broader Circuit Court rulings. Conservatives are in panic mode, and that is where the impetus for this ridiculous law came from.