Sorry, dude, they'll arrest you whether you're a citizen or not if they see you commit a crime and they're interested.
FWIW every police officer has "limited police powers" - the statement is vacuous. Federal police don't usually arrest for local law violations, local police don't usually arrest for federal law violations, etc.
So "limited police powers"? Well yes, they won't write a parking ticket, but they'll shoot your ass. I'd be wary of telling people that ICE agents have "limited police powers."
Using the left-leaning screed propublica as a reference is foolish.