I will not comment on the politics of the current administration but will make some remarks having recently travelled via the US to/from international destinations. As some of you are aware, I'm Canadian, and one of the things us Canadians love to do is to travel via the US internationally as fares tend to be a hell of a lot cheaper than flying direct. Most recently I flew to South America to visit my girlfriend, and booking less than 3 weeks out (and in need of earning Qantas SCs) American offered a decent open jaw between Toronto to Santiago and Curitiba, Brazil back to Toronto so I booked it (this by the way was after the tariffs on Canada and the president's numerous remarks on the 51st state).
Flying to the US from Canada I wasn't worried as the CBP are not allowed to detain anyone at a pre-clearance facility. And surprisingly my interaction with the border was the smoothest it ever was (I have Global Entry). All they asked was purpose of travel, and I just stated connecting via US to international destination and that was it. On the way back from Brazil, I was a little concerned because CBP can detain you if arriving into the US from abroad and there were reports of people being detained (or worse) at CBP facilities. As a precaution, I had the Canadian consulate on speed dial and WhatsApp should anything transpire (realizing it was less than a 0.001% chance of that happening but that is still more than 0% risk I had under sleepy Joe). Surprisingly, this interaction with CBP was even smoother, they just asked if I had anything to declare, I said no and that was it.
What I will also note is the immigration hall both at Toronto's pre-clearance and at Miami were eerily quiet and the border officers did not look like they were enjoying their work, but maybe that's me inferring something that isn't there.
To the question of this thread, my rule now is, the US is not my travel destination, although I may transit through it. I was planning on spending a week in Hawaii or Puerto Rico and now that's off the cards. There's too much uncertainty travelling to the United States right now, with rules constantly changing.
-RooFlyer88