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Former Bush White House official John Yoo responded to the mayor of Oakland, Calif., warning illegal immigrants about a pending ICE raid.

Yoo pointed out the United States "had a civil war" when "state officers impeded federal law."

Mayor Libby Schaaf (D) warned Saturday about the impending Immigration and Customs Enforcement raid across the Bay Area.

Tucker Carlson said that ICE officials told him 864 illegal aliens and public safety threats remain at large in the northern California city.

"It's like telling bank robbers the cops are on the way," Carlson said.

Yoo, who served in the Justice Department and now teaches at the University of California-Berkeley, said that "state officers cannot obstruct federal law," noting that "we had a civil war over this."

"You have mayors who are encouraging the subversion of federal law," he said.

Yoo added that Schaaf and others like Chicago Mayor Rahm Emanuel (D) are "coming very close to obstruction of justice."

Carlson also offered descriptions of some of those ICE was unable to nab this month in Oakland.

One man is allegedly a Honduran citizen arrested for cocaine possession and having sex with a minor.

Another is a Mexican national who was previously arrested for driving under the influence and smuggling.

Both people were previously deported but returned to the U.S., Carlson said.

Watch more above.

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