I went on Google maps and followed the CN from La Crosse WI to Wausau WI. A travel by rail of about half a day.
There are over 20 towns along that route. Some pretty good sized towns.
Granted, they would cut them in half, do a half hour speech at each and get off at Wausau a fly out.
So it takes him a full day. They cant stop him. Want to know why? Its interstate commerce lines controlled by the feds-his cabinet.
They can stop him from holding rallies indoors though.
So what? He maybe gets smaller crowds-which I doubt, because they will line those tracks for MILES to just get a look.
Take a look and see if its an old idea. Not that I like Wiki..but its quick anyway.
https://en.wikipedia.org/wiki/Whistle_stop_train_tour