 I'm Mark Remillard. In a major win for the conservative legal movement, the Supreme Court on Friday reversed a decades-old ruling that put a thumb on the scale in favor of federal agencies when interpreting statutes from Congress. This is a landmark decision upending four decades of jurisprudence, a doctrine known as Chevron deference. It was named after the oil and gas company that had a key environmental case before the court 40 years ago.