It's probably safer to not presume...

If you watch the video he goes on rambling about how "MIT graduates" go "bing bong boom" and shoot down an incoming missile "and then it's gone."

So yes, he seems aware it's a missile intercept program and not a literal physical dome.

he knows that Israel's "Iron Dome" isn't LITERALLY a dome, right?

This is Trump. That statement is NOT a given by any means. Odds are he does think exactly that.

I can't wait till his supporters start the, "he isn't being literal" thing again until he says the, "THE DOME JUST GOT 10FEET TALLE'r"

further, the “iron dome” of israel wouldn’t cover the state of florida. can you even imagine the logistics of trying to install one to cover the continental united states?

He thinks radar invisible jets can’t be seen by the human eye

https://www.msnbc.com/rachel-maddow-show/maddowblog/trump-genuinely-seems-believe-f-35s-are-literally-invisible-n1131361

By this logic, Margaret Thatcher isn't really a lady.

The great iron curtain, it can be seen from space!

I'm not saying Trump's any kind of actual "stable genius", but he's not as dumb as he acts. Just like George W Bush did, he plays social media, exploiting what I like to call the "pro wrestling fallacy" that liberals fall for every time.

Back in the nineties, seemingly educated, largely-Democrat-leaning people would talk about how dumb wrestling fans were, since it's all obviously faked. The largely-Republican-leaning wrestling fans knew it was fake, it's a show ffs, they aren't five year olds, and they naturally felt really insulted, contributing to the growth of a divide that we see today - redcaps against the rest of us. You'd even get people passionately arguing that it's real, maybe to feel like they're kind of part of the show, maybe just to troll the "liberal elitists" who were looking down on them.

Every time Dubya said something like "misunderestimated", "is our children learning", or "catapult the propaganda", we all made fun of it, it was talked about on the talking head shows, maybe even a bit on Saturday Night Live. To us, he looked dumb, but his messages got more circulation, his name was said more, and the people who already felt this (actually ivy-league educated scion of a wealthy elitist family) was just a regular guy they could have a bear with, people who could empathize with not having the perfect words all the time, they felt like we were making fun of them - which, in a way, we were. They loved him for being one of them.

In a lot of ways, Trump has just taken that to the next level. He's a master of getting us to attack him, in a way that make large parts of the country love him, and it works.