Here's a great example -- both doctrinally as well as normatively -- of how Chevron deference works.
The U.S. Department of Justice issues a press release about Dr. Harkonen. Dr. Harkonen asserts that the press release contains demonstrably false information about him. He finds a statute that says that federal agencies are required to develop effective administrative procedures "allowing
affected persons to seek and obtain correction of information
maintained and disseminated by the agency." So he asks the DOJ to remove the false information about him, or at least allow him an administrative procedure to try to prove that the stuff is false.
But the DOJ says that its press releases are categorically exempt from the statute because they don't really count as "information . . . disseminated by the agency." So it tells Dr. Harkonen to pound sand.
The Ninth Circuit agrees.
The statute's ambiguous. An agency (OMB) is entrusted with interpreting it. It has done so. While perhaps erroneous, its construction is at least reasonable. End of story.
That's how Chevron deference works. A concise little opinion by Judge Noonan explains it.