My friend from Barbados is studying to be a citizen and was very insistent that an American has a right to carry a shotgun on his person at all times. I said go ahead and please do it one day and watch what happens *LOL*
Arizona is an open carry state. About three weeks ago one of my coworkers stopped by the local gun store on his way home from work and purchased an AR-15. He then continued on his five mile ride home -- on his bicycle, with the AR slung over his shoulder. None of the local cops accosted him, but maybe that's because he's 6'8" tall.
Hey, but he knows what to carry. 12, 16, or 20; duck and cover.
Your friend is correct. Just because a right, protected explictly by the Constitution, federal and in most cases state as well, is violated on a routine basis, doesn't mean it doesn't exist.