The U.S. Supreme Court on Thursday blocked subpoenas from congressional Democrats for President Donald Trump's personal and business financial records but kept open the possibility that they could ultimately be enforced.
Chief Justice John Roberts, in a 7-2 opinion, reversed a lower court decision upholding four congressional subpoenas for the records, saying that it failed to adequately account for "weighty concerns regarding the separation of powers."
"The court did not say congressional subpoenas are constitutionally barred," Claire Finkelstein, director of the Center for Ethics and Rule of Law at the University of Pennsylvania told ABC News Live. "What it did say is that Congress didn't do its homework in figuring out exactly what it needed the documents for."
Three Democratic-led House committees have sought a sweeping array of Trump personal and business financial records -- more than 10 years worth, many predating his time in the White House -- including financial statements, loan engagement letters, bank statements, credit card statements, personal checks, loan applications and tax returns.
The lawmakers have said the information is critical to drafting federal ethics laws concerning the presidency, anti-corruption legislation and campaign finance rules. They are also continuing to pursue possible improper financial ties between Trump and Russia.
"We have never addressed a congressional subpoena for the president's information," Roberts writes. "We have held that each house has power to secure needed information in order to legislate," he added.
At the same time, the Roberts concluded that the power is not unchecked: "Without limits on its subpoena powers, Congress could exert an imperious control over the executive branch and aggrandize itself at the president's expense, just as the framers feared," he said.
Roberts said a lower could would need to perform additional "careful analysis" using criteria laid out in his opinion to determine whether or not they serve "significant legislative interests of Congress" and respect the unique burdens of the presidency.
"He's basically saying that the president shouldn't be treated like any other litigant; that the courts need to take a close look at whether Congress really needs these documents from the president; whether there's anywhere else they could get them; and, whether there's a legitimate reason that they need them," said Kate Shaw, ABC News legal contributor and Cardozo law professor.
Justices Thomas and Alito dissented.
"Congress' legislative powers do not authorize it to engage in a nationwide inquisition with whatever resources it chooses to appropriate for itself," Thomas wrote. "The power that Congress seeks to exercise here has even less basis in the Constitution that the majority supposes."
President Trump's legal team called the ruling -- along with a decision in a related case on a New York grand jury subpoena -- a legal victory.
"We are pleased that in the decisions issued today, the Supreme Court has temporarily blocked both Congress and New York prosecutors from obtaining the President’s tax records. We will now proceed to raise additional Constitutional and legal issues in the lower courts," Counsel to the President Kay Sekulow said in a statement.
House Speaker Nancy Pelosi, seizing on Roberts' affirmation of Congress' subpoena power, cast the decision as a victory for congressional oversight of the president.
"A careful reading of the Supreme Court rulings related to the President’s financial records is not good news for President Trump," Pelosi said in a statement. “The Court has reaffirmed the Congress’s authority to conduct oversight on behalf of the American people, as it asks for further information from the Congress."
"We will continue to press our case in the lower courts,” she added.
House Democrats face protracted litigation, which could potentially return to the Supreme Court, over the scope of their subpoenas and implications on the separation of powers. The lengthy process all but guarantees the committees will not receive the documents before the fall election.
"An important win today for the pillars of separation of powers and federalism," tweeted Carrie Severino, president of the Judicial Crisis Network, a conservative legal advocacy group. "These values are at the very heart of our Constitutional structure, and today they were upheld in a 7-2 opinion authored by the Chief Justice."
In a separate but related case handed down just minutes before, Roberts, writing for a 7-2 majority, said Trump did not have absolute immunity from subpoenas for his tax returns and other financial records sought by Manhattan District Attorney Cyrus Vance in a grand jury investigation.
"The conventional wisdom that this would be a split decision held: the president doesn’t have absolute immunity from state grand jury subpoenas but Congress doesn’t have carte blanche to engage in a fishing expedition against the chief executive," said Ilya Shapiro, a constitutional scholar with the Cato Institute. "Both cases will now continue, and won’t ultimately be resolved until after the election."