How Does Roberts Interpret the "Everything Clause"

Known more formally as the Commerce Clause, it's been used to justify countless federal laws covering everything from civil rights to endangered species.
For many conservatives, the clause has long been a sore point. They believe Congress and the courts have interpreted it too broadly, leading to sweeping federal regulations that the Founding Fathers never intended.
Democrats and liberal groups say Roberts' opinion in a quirky case involving California toads suggests he sides with the conservatives, has a narrow view of the clause and would strike down many federal laws.
"That theory could substantially cut back Congress' power," said Elliot Mincberg, vice president and legal director of the liberal group People for the American Way. "It could mean significantly limiting the ability of Congress to pass laws protecting civil rights, safety and the environment - and throwing out laws that already do that."