You do you but for me “we’re building concentration camps now” kind of invalidates previous behaviour, similarly to how I can think really well of someone most of my life but if they then decided to stab someone I’d probably change my opinion.

When someone says "concentration camps" they're conjuring images of emaciated prisoners being worked to death, arbitrarily murdered, and in the worst cases systematically killed at an industrial scale.

It's obviously not a valid comparison to a US migrant detention center, even if you feel that that detaining migrants is immoral. You don't strengthen your argument with that kind of hyperbole, instead my reaction is an unavoidable sense of disgust and a worry that people who do this are playing into the watering-down of history in the name of getting a short-term emotional reaction.

You can easily argue against the way the US handles immigration, especially under Trump, without falling into the trap of extreme hyperbole.