> The US. remain as unwelcoming to visitors as they have been since 2001
Strangely the stats don't back your assertion. Wouldn't being "unwelcoming since 2001" result in a decrease in travel?
https://en.wikipedia.org/wiki/Tourism_in_the_United_States#V...
This is meaningless without a denominator. How much has international tourism increased in those years? What percentage of international tourists visited the US before and after 2001?
I’d look for a change in slope. A permanent change that adversely affected tourism would decrease the slope, but maybe not so much as to make it negative.