Rand Paul’s negative vote on the Mullin nomination gave the Democrats an opening. If they remained united and voted against the nomination, they could delay it indefinitely. That in turn would give them some leverage in the negotiations over ICE procedures.
But Fetterman voted yes, and that was that. Maybe he thinks having ICE goons dominating the streets of blue cities is a good thing. Hey, he supported killing thousands of civilians in Gaza for no obviously good reason, so why not?