No, they woke up one morning and thought "Damn, this president is doing everything he can to strip American citizens of their rights under the Constitution. I'd better get prepared to defend my freedom".[
Of course it won't happen. The gun manufacturers, with the assistance of the NRA, long ago let the genie out of the bottle.
The "genie" was let out of the bottle long before there was a NRA and most firearms were imported from abroad. In fact it was the Founding Fathers of the United States of America that determined that the people have the right to keep and bear arms because it was "necessary for the security of a free State". Go read the Bill of Rights.
You misunderstand what I am talking about. Fifteen years ago, it was estimated that there were 80 million privately owned guns in the U.S. That number today is estimated to be at least 300 million. What? Do you think people suddenly woke up one morning and thought "damn, the Constitution allows me to own a gun. I think I'll buy one".