Went to the US in November, and also earlier in the year.
I think that the ease or otherwise of the border crossing depends on two things - where you're entering the US, and who happens to be at the desk.
For a start, the queue for non-US citzens at passport control at JFK - which is rarely less than an hour - was even longer. This was partly because of the lack of staff (the whole shutdown thing) but also because each incoming person was taking ages to process. So where the queues are long, they're likely to be longer. Where they used to be short, they're likely to be long.
As it happened, the guy on our desk was some kind of freak who'd got through Passport Control School thanks to a series of accidents and oversights. Usually those people are trained to be unsmiling, curt, offhand, monosyllabic and surly. This guy was chatty, friendly, jocular and engaging, and even recommended an Italian restaurant downtown. I suspect he's been fired. The feared inspection of Whatapp and Facebook didn't happen. And anyway I'd deleted Whatsapp as mine looks like Jon Stewart's ideas book.
Friends going through other airports have has less pleasant experiences.
As to the US itself, yeah, I think the vibe has changed. It's almost impossible to engage without the Great Divide coming up at some point. Which means, if you have a view one way, you have to decide what to do if you come across someone who has a view the other way. I don't think it's unsafe there, but it is rather fraught.
Then there's the guns. Then there's the omnipresent smell of weed. Then there's the mad cost of everything, which was a shock even to a Londoner.
Honestly, if it weren't for Dairy Queen, I might not go at all.