Even worse: The Trump administration claimed international airports as part of the border. (I saw that once, months ago. I do not know what the legal state of that claim is, or even whether it is currently part of their theory of what they are allowed to do.)
I can't find any definitive information on this. Disturbing if true.
Setting the “100 mile” thingamajig aside - why wouldn’t you consider an international airport part of your border? It is a port of entry.