The case of Texas Pipeline v. FERC involved a challenge to natural gas regulations as beyond FERC’s statutory authority. The Court found that the regulations were beyond that authority, and accordingly, did not reach any issues where agency deference under Chevron could be appropriate. See Op. at 5 (“[A]gencies cannot manufacture statutory ambiguity with semantics to enlarge their congressionally mandated border.”) The Fifth Circuit has taken a conservative view of agency opinions about statutory authority in other thoughtful opinions, see, e.g., Mississippi Poultry v. Madigan, 31 F.3d 293 (5th Cir. 1994) (en banc) (construing the term “same” in statute governing regulation of poultry processing).