Constitutional arguments that seem as dry as dust can have momentous consequences. On Monday, the Supreme Court’s nine fine minds will hear oral arguments about the meaning of “the” and “happen.” What they decide could advance the urgent project of reining in rampant executive power.

“The president,” says the Constitution, “shall have the power to fill up all vacancies that may happen during the recess of the Senate” (emphasis added). Monday’s case concerns whether Barack Obama made recess appointments when the Senate was not in recess, and made them to fill vacancies that did not happen during a recess.

In 2012, the National Labor Relations Board (NLRB) rendered a decision adverse to a soft-drink bottler in Yakima, Wash. The bottler asked the court to declare the NLRB’s intervention unlawful because the board did not have a legitimate quorum, three members having been installed by Obama when the Senate was not in recess as the Framers understood this term.

Republicans, wanting to block some Obama nominations, used a practice Democrats used in 2007 when they controlled the Senate and wanted to block some George W. Bush appointments. Operating under a unanimous-consent agreement — no Democrat objected — pro forma sessions occurred Jan. 3 and Jan. 6 of 2012. Obama declared the Senate in recess Jan. 4 and made his NLRB appointments, thereby disregarding the Senate’s determination of the rules of its proceedings and the settled practice both parties have used to remain not in recess even when most senators are away.

The Obama administration argues that the word “happen” is a synonym for “exist.” And it rejects the argument that an intra-session Senate break is a synonym for “adjournment,” not “recess.” This, however, ignores the reasonable reading of the definite article: Recess appointments fill vacancies that “happen,” meaning come about, during “the” recess of the Senate — the one break that occurs between sessions, which, until the Civil War, usually lasted only three to six months.

1 of 16 Full Screen Autoplay Close Skip Ad × Tom Toles draws the Supreme Court View Photos A collection of cartoons about the high court. Caption A collection of cartoons about the high court. June 27, 2013 Tom Toles Buy Photo Wait 1 second to continue.

The first president made the first recess appointment in the first year of his first term, in 1789, when travel was slow and arduous, and Congress was usually not in session. The recess appointments clause was written when conditions made such a power crucial. Obama, however, contends that in today’s world of instant communication and easy travel, he deserves a much larger — almost unlimited — recess appointment power.

His administration argues that “at least 14 presidents have, collectively, made at least 600 civilian appointments (and thousands of military ones) during intra-session recesses.” But Obama’s action regarding the NLRB is characteristic of his aggressive expansion of presidential power. He is the first president to make recess appointments when the Senate was convening pro forma sessions every three days, and he has articulated an anti-constitutional defense of his aggression:

“I refuse to take no for an answer. When Congress refuses to act . . . I have an obligation as president to do what I can without them.”

If he really can refuse a “no” answer, then the Senate’s role in the appointment process is vitiated. Now the court should apprise him of what he cannot do without Congress. Which means a Madisonian dialectic is occurring: The executive’s usurpation of power has provoked the legislature, precipitating an overdue judicial intervention to clarify constitutional boundaries. The Constitution’s text, and perhaps its original meaning, may be at odds with historical practice.

Because the ability to defeat by filibuster some presidential nominees has recently been restricted, perhaps not for the last time, presidents will have less need to resort to recess appointments. Nevertheless, were the court to uphold Obama’s action, two of the Senate’s constitutional powers would be substantially reduced — the power (which the House also has) to “determine the rules of its proceedings,” and the power to reject presidential nominees.

Many presidents have chafed against limits to their power, but in progressive presidents normal political ambition is alloyed with a validating ideology. Woodrow Wilson provided the progressive template by disparaging the separation of powers as an anachronistic impediment to the presidential power requisite for the modern age.

Monday’s argument will be another manifestation of America’s intermittent efforts to tame executive power, efforts that predate nationhood: The Declaration of Independence is a menu of complaints against “a long train of abuses and usurpations” by “the present King of Great Britain.” The present president’s cavalier approach to statutes (as with his unilateral rewriting of the Affordable Care Act) and the Constitution (see four paragraphs above) make Monday’s argument important.

Read more from George F. Will’s archive or follow him on Facebook.