Lots of blacks own guns for personal protection and want to keep that right intact. Obama knows to support the 2nd amendment and yet also throw it back onto local communities to make their own gun control laws. It is a win-win for him. He keeps the black supporters happy and throws the anti-gunners a bone.
There are also a lot of fairly conservative Democrats in the south, in particular, that are strongly pro-gun. He can’t risk alienating them just yet if he wants to win in the fall.
That’s also why you see a few Democratic senators taking a more conservative line on the 2nd amendment. They know that if they want to keep their job, that’s one issue that they can’t cross the line on.
These is no such thing as supporting the Second Amendment and then telling the states to decide. It's already settled at the federal level and the states cannot pass any laws which are in conflict with the Constitution. The Second Amendment is part of the Constitution, in case there are some that still don't acknowledge that.
Moreso, because the Second Amendment is mentioned specifically as an amendment not to be infringed as well as a law that states that the Constitution/Bill of Rights is the supreme law in spite of any Thing that the states might try to do concerning the right to keep and bear arms. Without equivocation.
American Citizens have been long-suffering regarding these attempts to immasculate the people. We haven't done anything about it at this late date because we are really curious to see what their end game plan is. Well, maybe just a little more than just curious.