Realistically they have that control now. They take what they want in taxes. They pass bills that cost us even more. If they really wanted our guns and came to get them would you shoot the local police officer just to defend your right to keep your gun? Because after you do that you are dead or in prison and your family is hurt by it.
The problem for them is that numerous police have stated that they would NOT enforce gun confiscation. So, the powers that be have to find a different way to confiscate firearms.