Dave, there was a long open letter from Rick Steves, a famous American travel writer and guide (and liberal proponent of many things, so this is no surprise).

This bit from the middle of the piece:

With all of this taken into consideration, if you feel strongly that, in good conscience, you can't continue to do business with a company that's based in the United States, we regretfully but respectfully accept that decision. Godspeed, keep on travelin’... and we hope our paths cross again when things get better.

But if you're looking for a reason to continue doing business with Rick Steves' Europe, let me offer this reassurance: While we, like you, are doing everything we can to push back against the dangerous and reckless actions of the US president, we also remain fully committed to our mission of teaching good travel, fostering people-to-people connections, and striving to create better citizens of the world... one trip at a time. If that's the version of "American values" that you support, we'd love for you to join us — and I believe you’ll find that the vast majority of your fellow tour members, regardless of nationality, share your values.