I’m certain this is like his “invisible jets” stuff he is always spewing about, where someone demonstrated our military being able to protect the US from outside missile attacks by showing him a picture with a “dome” over the US to illustrate how it would be all covered or something. And since he isn’t all there these days he thinks of it as a literal “dome”, just like the jets are actually invisible (not just to radar).

Edit - ha even dumber! I see someone mentioned the Iron Dome over Israel as probably what he is trying to convey in his word salad.