Only gun owners are concerned about preserving the 2A.
I understand the sentiment. But honestly, some non-gun owners are concerned about preserving the 2A too, and deserve some credit for that. People I know who don't own guns believe people should have the right to own them, and they're not in favor of all the gun control that's been discussed after each shooting. I had a conversation with one friend who is generally pro 2A but said he didn't understand why I was so opposed to UBC. I explained the concept as I understand it and he said that made sense and now doesn't think UBC would be very effective at all.
But this thread has devolved into more an argument over choices and priorities. To most of it is one of the most important issues given the non-stop pressure from the left to add more gun control. To some of us, other issues like gay rights, teaching evolution in science class, and a less interventionist foreign policy is more important than the 2A.
As I said. The next president will likely nominate more than one SCOTUS justice. Some people want that nominee to be a 2A supporter. Some people think "social justice" is more important than the 2A. You can't have it both ways. HRC will appoint a strong anti-gun justice to the bench.