Comments by "Cinderball" (@cinderball1135) on "OH NO: Trump Doesn't Understand "Per Capita"" video.

My guess would be that the 38M figure was put in front of him by an ignorant, useless staffer - the type of incompetent who would never get fired by Trump, because they're too stupid to find the inconvenient facts that might get them in trouble. I somehow can't imagine Trump himself even having the wherewithal to put Seoul into a Google search (without spelling it "Soul", anyway).
1