But, how do you know that the same Americans traveling to Asia are also tolerating said policies/politicians? I've had the same next door neighbors for 15+ years, and I have no idea what policies/politicians they tolerate/support. Much less the random person walking down the street.

I'm speaking from personal experience. I have travelled a lot, and I've noticed this as a pattern over what must be hundreds of people I've talked to at this point. I don't really know if my sample is indicative of the US population--I'm just puzzled by what I've seen.