While Americans enjoyed Fourth of July festivities, they probably gave scarcely a thought to something that has shaped their country from its beginning, sometimes explosively. It spawned the earliest political parties, crescendoed into the Civil War, and wove its way into the long struggle for civil rights.
In a word, it's federalism - the often tense division of power between state capitals and Washington. It resurfaced with some force recently in a trio of Supreme Court decisions.
The court was weighing whether to allow lawsuits against states for patent infringement, unfair competition, and noncompliance with federal labor laws - fairly mundane stuff. But the verbal fireworks between the five-member pro-states majority and the four dissenters showed that federalism still carries an emotional charge.
Justice Anthony Kennedy passionately voiced the majority's view that the country's Founding Fathers meant to confer on the states a sovereignty co-equal with that of the federal government. "Theirs," he declared, "was the unique insight that freedom is enhanced by the creation of two governments, not one."
Justice David Souter, in dissent, roundly rejected such deference to the "sovereignty" of the states. That notion, he said, cannot override the basic right of citizens to seek a remedy in court when deprived of a benefit afforded by law. It made no difference, in his view, if the party doing the depriving was a state government.
The oratory could soar even higher when the court reconvenes next fall. Among the cases on the docket is one involving state compliance with federal laws against age discrimination. That case could open a large door through which the five justices who favor an expanded definition of state sovereignty might charge.
Federal civil rights legislation rests on the 14th Amendment's guarantees of "due process" and "equal protection of the laws." Statutes prohibiting discrimination based on race or ethnicity should be safe from challenge. The intent of the post-Civil War amendment, after all, was to ensure the rights of freed slaves. But age, gender, and other bases for discrimination have been brought under the 14th Amendment's umbrella by Congress over the years. Will such matters be considered best handled by the states?
And how about the vast array of federal laws telling the states how they must behave in areas ranging from the environment to labor practices?
For all the fire and sparkle in their words about federalism, however, the Supreme Court justices are hardly wild-eyed radicals. They're not likely to attempt a rollback of federal jurisdiction to pre-New Deal days. But the conservative majority clearly is serving notice that Congress had better pay close attention to how it writes laws that obligate the states.
That's not all bad. State governments, by and large, are more enlightened and efficient today than they've ever been. Their creativity as "laboratories of democracy" should not be encumbered by Washington. At the same time, the federal government remains the guarantor of the most basic rights, unfettered commerce, and national security.
Adjusting federalism's balance - according to the needs of the times - is a perpetual, and often delicate, part of American democracy.