Should local law enforcement (LLE) also not hold over individuals wanted for mail fraud, kidnapping, bank robbery, child pornography, credit card fraud, computer crime, federal hate crimes, tax evasion, counterfeiting, illegal wiretapping, museum art theft  (to name a few) except in the case that those also violate a state law?
The sole reason that I can see for choosing to ignore the federal government on this point is that of fostering relations with the community to better fight local criminal activity.  That is argument is tenuous, at best, as I see it, in that it pits LLE against federal law enforcement.  Better to change the law at the federal level than force local law officers to become ICE agents.  In this, I do think that those incarcerated for local law violations should be remanded to the feds if there is an outstanding warrant.  Give ICE three days to collect the person on those grounds.
I disagree with DiNardo on path to citizenship, though; legal residency, I'm OK with.