Legal minutiae do not get any more minute than arguing over the definition of the word "happens."

At oral arguments Monday in the case of National Labor Relations Board v Noel Canning, Justice Elena Kagan at one point suggested that perhaps the meaning of that particular word has changed since the Constitution was written.

That would indeed put a different spin on the section that reads: "The president shall have power to fill up all vacancies that may happen during the recess of the Senate."

Justice Antonin Scalia argued that, no, the word's meaning has not changed in the preceding two centuries. None of Kagan's fellow liberal justices took up her argument and the court quickly moved on to other points.

Still, it couldn't have been a good sign for President Obama that one of his own Supreme Court choices was grasping at straws like this. The Noel Canning case could result in major rollbacks of executive power, returning authority to the Senate in the process.

Essentially the White House's position is that it has a right to install any federal appointments it wants, regardless of the Senate's advise and consent role. If the Senate says no, Obama can later deem it to be recess and then make the appointments.

That is not how the White House characterizes it, of course. Solicitor General Donald Verrilli’s main argument was that the Constitution's text was "ambiguous" enough that the president’s actions were ok.

"The NLRB was about to go dark," he told the justices. The real problem was the Senate's "intransigence," he argued.

He struggled throughout the oral arguments though as even liberal justices like Stephen Breyer expressed serious skepticism about this executive power grab.

"I can’t find anything that says the purpose of this clause has anything at all to do with political fights between Congress and the president," Breyer said. If they cannot agree, "that's a political problem, not a constitutional problem."

Even Kagan, prefacing her discussion of the true meaning of "happens," conceded to Noel Canning attorney Noel Francisco: "[If] you look only at the language and you look only at our own modern view of what happens, that surely seems to favor your position."

The case technically involves whether three 2011 presidential recess appointees to the NLRB, which oversees federal labor law, are valid, given the fact that the Senate was not technically in recess at the time.

But as Breyer noted, the underlying dispute is really political. That is, the president — a former constitutional law scholar — was not willing to accept that the Senate would not approve some nominees because Republicans rejected them.

After all, the president could have pulled the nominations and tried to find compromise picks the Senate would have approved. Obama never tried any such horse trading. If the Republicans were being intransigent, so was he.

Actually, Obama did not even bother to wait until the Senate had voted on the NLRB nominees. He made the nominations on Dec. 13, 2011, and appointed them on Jan. 4, 2012, just three weeks later. The Senate never filibustered them. They never even had time to hold hearings.

As far as Verrilli's claim there was an emergency, well, NLRB also lacked a quorum from 2008 through March 2010. This was thanks to a delaying tactic pioneered by Senate Majority Leader Harry Reid, the same guy who changed the rules to benefit Obama last year. Republicans were using the same tactic against Obama.

During the first part of the 2008-10 period, then-Sen. Obama seemed to have no problem denying then-President George W. Bush's recess appointments. The difference was that Bush decided not to challenge the Senate's advise and consent role.

As Justice Scalia noted, the appointments clause has only been assumed to be ambiguous "by self-interested presidents."