Afraid for US

Yes, the US has always been more tolerant of undocumented workers especially in the farming and construction sectors. The issue here is the rounding up without due process. The fact that Trump aims at deporting 11 million people is clashing with the capabilities available to process the cases properly. His choice is therefore 'sod it then, who cares about rights'. That's what absolutely needs to be fought against. It's such a slippery slope because it sets precedents for a state that does not abide by rule of law and replaces it with arbitrary decisions from shady unaccountable organisations that no one can challenge (in the name of 'getting shit done'). I see the same slippery intentions here whenever Tories or Reform talk about leaving the ECHR. It's to be able to do away with due process. It's a practical yet EXTREMELY dangerous decision. So, the question is do you hate undocumented migrants so much that you're willing to get rid of your own rights as a citizen? I'd argue many Americans emphatically do not want that.

Done to death?
Get used to it because this situation is not going away any time soon and the reason we should all care about what unfolds in the US is that it's an international movement, a true globalist movement (oh the irony, right?) that seeks to export this authoritarian model to countries across the West. We're first in their line of sight.
In an interview with the BBC, Steve Bannon (still very much an influence in the MAGA world) was saying verbatim that 'you guys in the UK should do the same' when talking about rounding up immigrants without due process and deploying the army.
It's bad. And it's our fight as much as it is the Americans'.

To be honest I was amazed at the protesters - someone on the news was complaining that her dad was deported after living in the US illegally for ten years and he missed her birthday. A protester had a sign saying no-one’s illegal on stolen land. I can appreciate both sentiments but surely people understand that countries have borders and immigration rules? It’s not fair, it’s a lottery where you’re born, and yes if you go back to settlers times the occupation of Native American land and elsewhere was abhorrent, but it’s not feasible to just remove all borders on all countries - who’s going to pay taxes where? Who’s going to pay for teachers, police, roads, healthcare etc?
His language is abhorrent I agree, but I think a lot of his actions are half arsed - for now at least.
I agree it’s still a worry it starts off semi-acceptable then spreads, but he’s already losing so much support I’m not sure he could be the next Hitler…

What complicity of ordinary people?

As a Brit in the USA I’m actually more surprised at how much tolerance there is for illegal immigrants in the USA.
I actually think that the UK has much lower tolerance.
That said I think Trump is trying to provoke the annoyance that does exist and turn it to his own advantage.

Sorry but this has been done to death already. Everyone is concerned.