Politico published an article by Michael Waldman called "How the NRA rewrote the Second Amendment", which basically says everything I have been saying all along about that part of the Constitution.
Many are startled to learn that the U.S. Supreme Court didn’t rule that the Second Amendment guarantees an individual’s right to own a gun until 2008, when District of Columbia v. Heller struck down the capital’s law effectively banning handguns in the home. In fact, every other time the court had ruled previously, it had ruled otherwise. Why such a head-snapping turnaround? Don’t look for answers in dusty law books or the arcane reaches of theory.
So how does legal change happen in America? We’ve seen some remarkably successful drives in recent years—think of the push for marriage equality, or to undo campaign finance laws. Law students might be taught that the court is moved by powerhouse legal arguments or subtle shifts in doctrine. The National Rifle Association’s long crusade to bring its interpretation of the Constitution into the mainstream teaches a different lesson: Constitutional change is the product of public argument and political maneuvering. The pro-gun movement may have started with scholarship, but then it targeted public opinion and shifted the organs of government. By the time the issue reached the Supreme Court, the desired new doctrine fell like a ripe apple from a tree.