Ten years ago there was a case known as Obergefell v Hodges and the outcome of that case meant that same-sex marriage was legalised in the USA, but was not made federal law, however, it did mean that State law could not contradict that.  Then Kim Davis, a religious extremist county clerk from Kentucky refused to grant licenses to same sex couples and after she lost the case where she was sued by one such couple, she had to pay $100K in damages and $260K in penalties and spend six months in jail.  Now she is challenging the Obergefell v Hodges ruling and this is waiting to see if the Supreme Court will take it up and if they do which way they will rule - after the ruling in respect of Roe v Wade I would not bet against it.

Fortunately, during the Biden presidency an act was passed which means effectively that any same-sex marriage granted in one state must be respected in all other states and also that any previously granted such licenses must continue to be respected, so it would not be possible for a state which still has anti-same-sex marriage laws on their books, the majority, to retrospectively nullify any such license previously granted.  This means, assuming the worst case, that only a handful of states will still grant same-sex marriages and there will be a lot of people unable to travel to such a state - but any such license will be valid in all states.  The map below shows the situation with respect to state laws and this will be the situation if Obergefell is overturned-

Anyone who thought that trans people were the sole target, I hope you see that that is not and never was the case.