There’s a long and detailed explanation over on Reddit written by a speech therapist that details what probably happened when Trump screwed up the speech and claimed that soldiers defended airports in the Revolutionary War.
Tl;dr: due to Trump’s notorious inability to read and his inadequate vocabulary, he exerts all of his concentration trying to say what is written that he doesn’t really process the words until he has already spoken a good deal of the sentence. The author of the comment suggests that Trump got tripped up on the unfamiliar word “rampart” and conflated a line about “bombs bursting in air” with word “rampart” and came up with the familiar word “airport.”
