President Donald Trump, at his daily coronavirus briefing on Wednesday, threatened to use his Article II powers laid out in the U.S. Constitution to force Congress to adjourn so he can make recess appointments for vacant spots in his administration.

The Constitution does say a president can, "on extraordinary occasions" convene both chambers of Congress, or if the chambers can't agree on adjourning, "he may adjourn them to such time as he shall think proper." That means, if the Republican-controlled Senate moves to adjourn and the Democratic-held House refuses, Trump can step in to end the current session of Congress.

No president has ever used this power, according to a post at the National Constitution Center by University of North Carolina law professor William Marshall and University of Virginia law professor Saikrishna Prakash.

The Senate and House are currently holding pro forma sessions while both chambers are in recess during the COVID-19 pandemic, and lawmakers are not expected to return to Washington, D.C., until early May.

But on Wednesday, Trump accused Senate Democrats of holding up his nominations and complained the length of time it takes to get judges appointed—which his administration and Senate Majority Leader Mitch McConnell have prioritized—has resulted in a backlog for senators approving the officials he needs to respond to the pandemic. Trump has not tapped nominees for a number of his administration's empty positions, including secretary of Homeland Security.

"The current practice of leaving town while conducting phony pro forma sessions is a dereliction of duty that the American people cannot afford during this crisis. It is a scam," Trump said during the briefing. 

"We'll probably be challenged in court, and we'll see who wins," he added.

However, Congress has already agreed to adjourn the current session on Jan. 3, 2021, meaning there is no disagreement between the chambers—which could prove to be a substantial hurdle for Trump to clear if he chooses to push forward with the effort. The GOP-held Senate would also need 60 votes to agree to adjourn at a different date.

McConnell's office said in a statement obtained by several media outlets that he and Trump spoke earlier Wednesday about the president's "continued frustration" over stalled nominees, but suggested the top Senate Republican would not adjourn the current session.

"The Leader pledged to find ways to confirm nominees considered mission-critical to the COVID-19 pandemic, but under Senate rules that will take consent from Leader Schumer," the statement reads.

President Barack Obama was the last president to try and make recess appointments. But that move was challenged in the courts and wound up before the U.S. Supreme Court, which unanimously ruled in 2014 that the appointments were unconstitutional, citing the Senate's pro forma sessions during the recess.

"In calculating the length of a recess are we to ignore the pro forma sessions, thereby treating the series of brief recesses as a single, month-long recess?" Justice Stephen Breyer wrote in the court's majority opinion. "We conclude that we cannot ignore these pro forma sessions."

Breyer wrote the court found the text of the Recess Appointments Clause to be "ambiguous," saying it "does not resolve whether the president may make appointments during intra-session recesses, or whether he may fill pre-recess vacancies."

"But the broader reading better serves the clause's structural function," the justice continued. "Moreover, that broader reading is reinforced by centuries of history, which we are hesitant to disturb. We thus hold that the Constitution empowers the president to fill any existing vacancy during any recess—intra-session or inter-session—of sufficient length."

In a concurring opinion, Justice Antonin Scalia said he differed entirely in his interpretation of the clause, warning the majority opinion "transforms the recess-appointment power from a tool carefully designed to fill a narrow and specific need into a weapon to be wielded by future presidents against future Senates."

"The Recess Appointments Clause therefore is, or rather, should be, an anachronism—'essentially an historic relic, something whose original purpose has disappeared,'" the justice wrote. "The need it was designed to fill no longer exists, and its only remaining use is the ignoble one of enabling the president to circumvent the Senate's role in the appointment process."

This isn't Trump's first foray into constitutional powers over the current pandemic: Earlier this week, he claimed he had "total" authority to reopen the country, the vast majority of which has shuttered to prevent the spread of the COVID-19 virus. Constitutional experts rejected the statement, which is contrary to the Tenth Amendment, and Trump later walked back the comment.

Here's what some constitutional law scholars had to say about the president's most recent comments:

>> Jonathan Turley, constitutional law professor at George Washington University: "Senators of both parties should vote to support the congressional control over adjournment. Absent a 'disagreement' there is no presidential power to adjourn under Article II. A pandemic should not be an invitation for pandemonium. Indeed, we need regular order now more than ever." Twitter.

>> Steve Vladeck, professor at University of Texas School of Law: "Article II of the Constitution gives the President the power to adjourn Congress if—and only if—the House and Senate cannot agree on a date for ending the current session. But they have agreed—January 3, 2021. There's a reason why this power has *never* been exercised before….The Senate could always try to change that. But a motion to adjourn would be subject to cloture—meaning it would need at least 7 D votes. The majority could get *rid* of cloture by a simple majority, but I have to think this would be a bridge too far for at least 4 R senators." Twitter

>> Deepak Gupta, Supreme Court and appellate lawyer at Gupta Wessler: "This is all crazy. There's currently no disagreement between the House and Senate on when to adjourn sine die. And even if McConnell wanted to manufacture a fake disagreement for this purpose, that adjournment would require 60 votes—which he can't get. What am I missing?" Twitter

>> Josh Blackman, law professor at South Texas College of Law: "Noel Canning Redux: Justice Scalia wrote that the President could use the adjournment power to block Senate 'intransigence.' No President has ever adjourned Congress before. Yet at least. Yesterday, all the reporters called me to ask about whether Trump can order states to re-open. Today they will call about the Adjournment Clause. Trump has perfected the art of the troll. He can change the narrative with a single tweet or statement, and we forget about yesterday." Twitter