People arrested for disturbing the peace in the US won’t disappear or end up in a re-education camp where their organs may be harvested.[2] Hong Kongers are certainly fighting for the right to remain under common law, there’s a clear difference in theory and practice.
[1] https://en.m.wikipedia.org/wiki/Peace_(law)
[2] https://www.reuters.com/article/us-britain-china-rights-idUS...
I don't think people are trying to stick it to Trump. People have been angry about police brutality and police killing black civilians for a long time. The LA riots were 30 years ago, and things haven't really changed that much since then - there are still cases of the police killing people with far too much regularity. This is a political issue, but it's one that crosses party boundaries. People are only really angry about Trump because he's in office at the moment; if it was a different president they'd be angry at him.
In effect, he's arguing that rioting has been decriminalised in Portland without any popular vote and without any explicit decision ever having been made. If that's true it's unsurprising the police keep arresting people and they keep being released. The issue there wouldn't be the police. If Portland wants riots to be legal when the rioters support leftist causes, they should explicitly adjust the local laws to allow it.
That said, the link they provide states the guy was released "on own recognizance" which basically means he promised to turn up in court at a future date, albeit with no bail money paid. So it doesn't say charges were dropped.
The Portland Police are arresting people for disturbing the peace. So are the federal police, the only difference is the people they are arresting are being release because the Portland DA chooses not to press charges.
It's all political. I don't know about you, but I'd be more concerned about the Portland justice system being perverted just to stick it to Trump.
[1]https://www.mcso.us/PAID/Home/Booking/1506008/1517573