Well, how many of them are illegal immigrants?

Could be they don’t want the federal to know they even exist. Many gun owners are concerned about the many attempts by the Feds to disarm Americans. There is little to no trust in any of our institutions.

I don't consent to being governed so no vote except for Lord Jesus Christ

Oh, they're registered to vote, alright... just not in the elections that use ballot boxes.

I’m thinking voter registration should be automatic when you buy a hunting or fishing license and during the background check to purchase a firearm.