The goal is not gun control - that would simply be a bonus.
The goal is to legitimize the imminent organizing and revolt of the people demanding Trump's removal.
They very easily organized multiple "marches" consisting of millions of people; they will do it again.
This will then make it even more difficult for Trump to "go after his political enemies".
The optics are dismal and it will take a miracle to overcome this. But I'm sure the OIG has a GREAT report coming out that will make it all go away.