Ah yes, the Commerce Clause. I thought that might be what you had in mind.
Since the 1930s, the Commerce Clause has been a favorite of Democrats and Leftists in this country. They have used it to justify the expansion of the power and reach of the Federal government into all areas of life.
Setting aside the question of whether the gun store owner was engaged in "interstate commerce", do you see any limit on power of Congress under the Commerce Clause?
Explain how the paperwork involved is onerous, and leftist.
"Setting aside the question of whether the gun store owner was engaged in "interstate commerce", do you see any limit on power of Congress under the Commerce Clause?"
There is no limit given in the Constitution. The founder's assumed commerce would be regulated to flourish, not regulated out of existence, so no limit was given. As Franklin said at the closing of the Convention, that the Constitution wasn't perfect, it was left up to the future what folks would make of it.