Earlier quoted context omitted.
But shall-issue permits are only common in the first place because states were allowed to independently try it out. Up until the mid-90s, almost all states were either may-issue or no-issue.
Do you have a source for that? Gun laws have only gotten more strict in recent years, not less strict.
This is definitely not true at the state level, and not exactly true at the federal level either.
Every state to which I regularly travel is now "constitutional carry" - i.e., no permit needed at all. None of them were ten years ago.