Carrier delivery was started during the Civil War so that thousands of people would no longer have to line up at the post office each day waiting on news from their soldiers in the war.
People who oppose the constitutionality of carrier delivery are against national defense.
OK - I will stipulate that when the time machine is invented that takes us back to the 1860's, eliminates the internet, and starts the Civil War over again, MAYBE home delivery would be a good idea. If we can afford it.
In the meantime, equating opposition to carrier delivery to opposition to national defense makes you sound like a democrat trying to make a point.