I think you know why…
In case you were wondering if they want the Court to overturn Obergefell:
Ask yourself why he would say this. Is it possible that he thinks the Supreme Court might just overturn Obergefell? Of course he does. If he didn’t, he wouldn’t think there was anything wrong with voting for the marriage equality bill which simply codifies the Supreme Court’s decision. And he certainly wouldn’t see it as intimidation of the Supreme Court.
They know this is on the menu. It will take a little bit of work to shake up the consensus on marriage equality but I doubt it will take a great effort to detach the right from their very tenuous sense that gay rights are acceptable. They’re already doing it in Florida and it’s catching on like wildfire in red states around the country. It won’t be long until it’s back to being a polarizing issue. And then the court will strike.