I found out that in the 30s US built 2 flying aircraft carriers - USS Akron and USS Macon.

USS Akron
They both were destroyed by bad weather, though.

Anyway, what would've happened if these flying aircraft carriers would've become popular?
From the National Geographic:
In its heyday, the Macon was used for scouting purposes over the Pacific Ocean. Some historians believe that the attack on Pearl Harbor might have been prevented if the ship had still been in use.
Also, is it possible to build similar machines in these days? Nuclear powered flying aircraft carrier?