As Canadians, my wife and I refuse to travel to the US or take any flights that stopover in the US. We would love to go road tripping or get cheap flights to visit various places, but it's just off limits for us, possibly for many years, due to the ridiculousness of what is going on at the border and in the white house.
We watch cheap flight deals pretty regularly and have noticed we are seeing a lot more cheap flights to the US than normal, so it makes us think that perhaps the US is starting to suffer on tourism, but it could just be our biases.
As more people get fed up like us, tourism will wane, but I doubt it'll make a big enough dent anytime soon for any action to be taken, especially when it's spread across the entire US, so harder to see at once.