By Sahil Kapur 

The Supreme Court is scheduled to hear oral arguments on Monday in a case with potentially dramatic long-term implications for the balance of power between the executive and legislative branches.

The legal question is whether the president may temporarily appoint people to staff executive branch agencies when Congress is not conducting business but also not technically in recess — known as pro forma sessions. Noel Canning, a business based in Washington State, claims that actions taken against it by the National Labor Relations Board (NRLB) are invalid because they relied on the decisions of recess appointees to the board who were put in place during pro forma sessions.

A decision against the Obama administration “would overturn the long-settled understanding of the Recess Appointments Clause, upsetting the equilibrium between the political branches created by our Constitution’s framers,” said Elizabeth Wydra, the chief counsel for the Constitutional Accountability Center, a liberal legal advocacy group.

Wydra called the lawsuit “ahistorical and myopic.”

A ruling against the government in NLRB v. Noel Canning stands to invalidate a series of NLRB actions aimed at cracking down on unfair business practices. Depending on the scope of the decision, government actions taken under previous presidents may also be implicated.

The Supreme Court’s determination on the parameters of recess-appointment power has fewer short-term implications now that the 60-vote threshold has been eliminated for most nominees, allowing President Barack Obama to staff agencies without Republican votes (at least while Democrats hold the majority).

But the longer-term consequences are vast and unknowable. A sweeping ruling against the administration could strip Obama and future presidents of a vital tool to make departments and agencies function when senators are on holiday or won’t confirm nominees.

“If there’s a high-level executive branch vacancy — maybe a cabinet secretary — where the president really needs to get somebody into the job right away, there could be an issue if the Senate decides not to move the nomination forward,” said Caroline Fredrickson, the president of the liberal American Constitution Society.

The D.C. Circuit Court of Appeals sided with Noel Canning, invalidating the recess appointments and decisions made by the appointees. “Considering the text, history, and structure of the Constitution, these appointments were invalid from their inception,” read the decision by a three-judge panel in Jan. 2013.

All 45 Republicans have signed an amicus brief urging the Supreme Court to rule against the Obama administration and forbid the president from recess-appointing members during pro forma sessions. Senate Minority Leader Mitch McConnell (R-KY) has accused Obama of making an “unprecedented power grab” and stripping the Senate’s advise-and-consent duty with nominees.

Fredrickson cautioned Republicans to “be careful what you wish for,” saying they would some day be back in the White House and may have a hard time getting their team in place if they face a hostile Senate.

Norm Ornstein, a congressional scholar at the American Enterprise Institute, wondered if politics will influence the conservative court’s ruling, which is expected by the end of June. He observed that Chief Justices John Roberts and Justices Antonin Scalia and Clarence Thomas have previously been proponents of broad executive power under GOP presidencies.

“If you look at Scalia and Thomas and Roberts — these are all people with very significant experience in the executive branch, who in the past have been very protective of executive power and skeptical of congressional power,” Ornstein said. “But that was back when Republicans dominated the presidency and Democrats dominated the Congress. Now it’ll be interesting to see if these staunch originalists stand by their views. And I don’t know the answer to that.”

Ornstein speculated that if the Supreme Court rules against the Obama administration, “they’ll do the same thing they did in Bush v. Gore and say the ruling only applies to these circumstances.”