Your right that this is something he can get Republicans and Democrats to agree on. All any politician has to allude to is law, order and safety and the masses will shiver in erotic anticipation at the prospect of putting their neighbors in their place. Because they are pissed off anytime they see anything out of ordinary and want those people controlled and by controlled I mean RIGHT NOW!
If Americas government becomes more authoritarian and any resistance develops, I envision the government offering citizens necessities (food, fuel etc.) in exchange for their informing on gun owners, or anybody participating in any resistance activities. It's useful I think, to remember that if our way of life is attacked, that nearly half (possibly more)of our "countrymen" will be on the governments side. Many informants will be peoples own children.