An attempt to do so would result in State sponsored civil war declarations, and a military coup against the Federal government.
But anarchists can dream on...
***The Federal government can not “bring in the Army” against USA citizens.***
By the time the Government reaches this point of gun confiscation they will be able to do any thing they wish.
Remember, Liberals will be the ones in power.
So they'll use the Marines, who are not covered by the Federal posse comitatus act, and have a long histyory of such activity, from the recovery of the US Arsenal at Harper's Ferry from Abolitionist terrorist John Brown to guarding the US Mails from 1922-'27.
An attempt to do so would result in State sponsored civil war declarations, and a military coup against the Federal government.
That'd just result in another string of sudden and tragic air crashes involving Flag and General officers, with an additional few sudden *suicides*. Or hadn't you noticed?