Sheriff David Clarke blasted Newark Mayor Ras Baraka (D) for vowing to defy federal immigration law.
Baraka, who leads New Jersey's largest city, said President Trump was essentially making sanctuary cities "fugitive slave holders" by demanding they work with ICE to deport illegal immigrants or have their federal funds withheld.
"I've heard a lot of stupid things [but] comparing fugitive slaves to illegal immigrants is the gold standard of stupidity," Clarke said.
He said he wished Baraka could make the same remarks around 19th Century African-American icons Dred Scott, Nat Turner or Frederick Douglass.
Clarke said such men would disagree that slaves being returned to their masters was the same as illegal immigrants being sent back to their home country.
He said Baraka's remarks were the political left's latest way of "adding fuel" to the fiery illegal immigration debate.