He’s running out of constituencies that will vote for him, so, from desperation, he’s trying for the votes from prison inmates.
But, they’re not going to be voting for him, since, he would take away their preferred weapon in their profession, guns. Loser everywhere.
He's promised to take AR15s from John Q. Public, not prison inmates... in essence, Irish Bob is advocating better odds for the criminal element; the sharper ones will figure it out.