The Supreme Court's theme song during the 17-year reign of Chief Justice William Rehnquist has been a rollback of federal power to the states. So it was a surprise this week to see Mr. Rehnquist lead a 6-to-3 decision shooting down Nevada's plea for exemption from the US Family and Medical Leave Act.
Critics of the Rehnquist court have looked for holes in its states'-rights arguments; they thought they had found a big one in 2000 when the conservative majority overruled Florida's high court in ending the presidential vote.
But it's worth watching the Rehnquist logic more closely as he continues to force a historic shift in power across the political landscape.
His work can be summed up in this line from one of his earlier decisions: "The Constitution requires a distinction between what is truly national and what is truly local."
Drawing that line of distinction has played out mainly in court rulings barring state workers from suing a state for violating federal laws. States generally have "sovereign immunity," the Rehnquist court says.
But in the Nevada case, the chief justice found enough historical evidence of discrimination against women in the workplace - even in past high-court rulings - to let a federal law trump states' rights in regulating time off from work for both sexes to attend to emergencies. Dissenting judges said the evidence was weak.
When there's either widespread sexual or racial bias, Rehnquist finds the Constitution's "equal protection under the law" clause must overrule the clause that limits "the judicial power of the United States."
Case by case, Rehnquist's legal rigor is defining a new balance between the states and Washington.