I don’t understand this, could you please explain?
If marriage in one state is recognized in all states, and a driver’s license in one state is recognized in all states, then why not a CCW?
Because states choose to recognize marriage and drivers licenses, under certain conditions. Before the Supreme Court decision some states legalized gay marriage and other states refused to recognize those marriages. That is their right under the 10th Amendment. Kansas is a rural state and they will grant restricted drivers license at 14. But move to California and that 14 year old won't be able to drive. That, too, is their right under the 10th Amendment. CCW permits should be no different.