Every president has bloody skeletons, even Harrison who was only President for 31 days was an asshole whose political actions led to death and destruction.
Trump's are far more public and he's far more open and blatant than most in recent times about using the power of office to bend laws to his whims and gain access to the wealthiest people for his own personal benefit.
I still wouldn't put him as the worst. Maybe top 10-20, depending on how much 'it was the times' can be used to handwave the many loudly pro-slavery, pro-expansion, pro-slaughtering and raping whoever they pleased Presidents the US had had.
Even well beloved presidents like Abraham Lincoln have their skeletons - Lincoln authorised the largest mass execution in US history, of hundreds of Dakota people who had fought against American expansion. He actively pursed war with American Indigenous peoples while the American "Civil War" was going on.
The expansion of Presidential powers that Trump is taking advantage has been going on for decades. Yes ICE and the state of the immigration detention centres are horrible; however, while Trump expanded on their powers, he didn't invent them and he's just part of a long line of presidents doing that - Biden did it, Obama did it, the Bushes and Clinton... Trump may be louder about doing it, but he isn't alone in it.
I'm both American and British, and I'm entirely unbothered if English or other British people know entirely how bad ICE is, I'd rather we focused on what was on our doorstep rather than the bad habit of looking at the shitshow in former colonies to ignore what's going on here. The UK's own immigration detention centres have had multiple horrific controversies around sexual violence and deaths in state custody that get largely swept aside with people pointing at the US and Australia.
And yes, people can be illegal or undocumented immigrants on land that was lost in wars, abused treaties, and shady deals (like the ones Harrison did). An illegal migrant is just one whose migration doesn't comply with current laws - that's why many started as legal migrants and then fell out of compliance, sometimes intentionally like overstaying, and sometimes unintentionally when a law has changed and is retroactively applied. Whether we think the law or the government behind the law is justified doesn't change that and the horrific tactics used against them as we've seen in many countries wouldn't be better from a government on what was universally agreed was their land (if such a thing exists) compared to a country like the US.