Even a Supreme Court opinion throwing out President Barack Obama’s recess appointments to the National Labor Relations Board wouldn’t end the debate.

Justices from across the ideological spectrum seemed to have doubts during oral arguments Monday about the administration’s arguments, with the president’s power to get around Senate roadblocks to name his own team at stake.

The administration argued that the recess appointments were valid because the Senate’s practice of holding pro forma sessions every three days without conducting business was no different than being out of town.

An exchange between Solicitor General Donald B. Verrilli Jr. and Justice Elena Kagan put the argument into relief.

Kagan asked Verrilli if the Senate could convene for unanimous consent requests to name post offices and conduct “trivial business” to avoid the argument over the pro forma sessions.

“I think if they did business each of the three days, then you wouldn’t have a situation in which no business was conducted and you wouldn’t meet the definition of a recess, but that’s a different case than this one,” Verrilli said.

Kagan replied that if the rule defining what constitutes a recess would be “so easy to evade, [it] suggests that this really is — the question of how to define a recess really does belong to the Senate.”

“I think the problem with looking at it that way, Justice Kagan, is that that’s the end of the recess appointment power,” Verrilli said. “You write it out of the Constitution, if you look at it that way, because all the Senate needs to do is stay in pro forma session until 11:59 a.m. on January 3rd when that term ends and the next term starts and then there are no intercession recesses.”

Justice Ruth Bader Ginsburg seemed to share Kagan’s thinking.

“The Senate, I think to be candid, the Senate is always available. They can be called back on very short notice. So what is it that’s the constitutional flaw here?” Ginsburg said, questioning Verrilli. “It isn’t … that the Senate isn’t available. The Senate is available. It can easily be convened.”

Even if the Supreme Court decides it is within the Senate’s power to determine when it is in session, the president might still have a way to force through recess appointments. That would rely, however, on an untested constitutional provision that would appear to allow a president to force Congress to go home.

None other than Miguel Estrada, appearing as counsel representing the interests of Senate Republicans during the unusually long oral argument session Monday, raised that possibility. Estrada’s own nomination to the federal appellate bench was famously upended by opposition from Democrats.

“If the Senate had any view that it wanted to recess, they could have had a vote, and the issue would have ended up in the White House, in the lap of the president,” Estrada said. “He had plenary constitutional power to give himself an intersession recess by terminating the session and have a real recess appointment power if he could find somebody whose vacancy had actually arisen at the time.”

The same section of the Constitution that provides for the president to update Congress on the state of the union and to recall Congress into session to attend to urgent business also allows for forced adjournment when the two chambers fail to reach consensus on adjourning.

“In Case of Disagreement between them, with Respect to the Time of Adjournment, he may adjourn them to such Time as he shall think proper,” the Constitution states in part of Article II, Section III. Estrada wasn’t backing such a maneuver, but he certainly suggested it was a possibility.

A senior Senate Democratic aide said “it would be unlikely that Democrats would need to go down that road, given” that they have sought to ease the nominations process by lowering the threshold for overcoming a filibuster.

“This is the cockeyed way of going about the instruments of the Constitution. There is no power in the Constitution to use the Recess Appointments Clause to overcome the opposition of the Senate to the president’s nominees. And for all that we hear about today, which has to do with how the heaven will fall, and the parade of horribles, there is no parade, and there is no horrible,” Estrada argued.

Minority Leader Mitch McConnell of Kentucky was one of several GOP senators in the chamber for the oral arguments.

“The Court today was rightly skeptical of the Solicitor General’s inconsistent argument that the Senate is in session if the President wants it to pass legislation he supports, but the Senate is not in session if he wants to circumvent the advice and consent requirement of the Constitution,” McConnell said in a statement.

Sen. Mike Lee, R-Utah, said attending the arguments was like being a “kid in a candy store.”

“All three of the arguing counsel today had an enormously powerful command of the history of the exercise of the recess appointment power,” Lee said. “It was very interesting to hear how it had been viewed by the first few presidents, how it’s been exercised over the 225 years or so since the Constitution’s been in effect.”

Lee was optimistic about the chances for victory, suggesting the possibility of a unanimous decision backing the brief pro forma sessions, with closer rulings on other key questions.

During the argument, Justice Sonia Sotomayor elicited laughter for musing about the Senate’s work schedule.

“The Senate could choose, if it wanted to, and I think there might be some citizens that would encourage it to, to never recess,” Sotomayor said. “And to work every day, which … lots of people do.”

Humberto Sanchez contributed to this report.