As an American citizen that goes in and out regularly, I've never been given a particularly hard time (white, obviously fairly well-to-do, non-threatening) but I will say that I've thought for a long time the experience at border control is almost completely dependent on how the individual staff member approaches their job. In the past, some of them were perfectly fine and some were clearly cosplaying semi-fascist militaristic pricks. I shudder to imagine how their number will increase in this regime.
They used to pretty universally say, Welcome Home, which always made me feel a bit teary. These days they're more likely to regard you with suspicion for having left the country in the first place, and I found that during the Biden years too.