A federal judge in Sacramento repeatedly pressed the U.S. Justice Department on Wednesday to explain how California's so-called sanctuary laws improperly hamper federal immigration enforcement.

U.S. District Judge John Mendez of the Eastern District of California peppered the government's legal team, led by Chad Readler, with a range of questions exploring the interplay between California's laws and federal power.

The hearing, more than five hours long, resembled more of a trial at times than an injunction hearing. Mendez dove into minute details of the case, asking lawyers for relevant case law, citing arguments from the many amicus briefs, questioning the severability of provisions in state statutes and quizzing the sides with long lists of what appeared to be prepared questions.