The Supreme Court issued two landmark decisions today on President Donald Trump’s financial records. The first, Trump v. Vance, related only to a New York state criminal subpoena; the second, Trump v. Mazars, related to congressional subpoenas of Trump's tax returns.

In Vance, the court ruled that Trump's financial records may be subpoenaed by the New York district attorney’s office as part of a criminal investigation. It’s a devastating blow for the president. But Mazars was a tactical win for Trump, insofar as it likely means the courts cannot reach a final ruling on the issue in time for the November 2020 election.

The Mazars decision is the more nuanced ruling, and we’ll get to that. But let’s start with the Vance case, which elicited a rather extraordinary opinion from Chief Justice John Roberts.

Trump v. Vance
Roberts, joined by the court’s four liberals, wrote the majority opinion, which relied on precedent to conclude that the president has no special protection against turning over his papers to a state prosecutor. This is yet another decision this term that consolidates Roberts as the only really important power on the court — and as a justice who has decided to be sure that rule of law extends to Donald Trump.

The ruling started with the founding father we love to hate, Aaron Burr. Yes, the same man who was the nemesis of Alexander Hamilton, killed him in a duel, and went on to organize a conspiracy to create a new country carved out of the western part of the United States.

Burr was put on trial not for killing Hamilton, but for his alleged treason. The trial took place before Chief Justice John Marshall, by common consent the most important justice ever to have sat on the U.S. Supreme Court, and by far the most influential chief justice until, well, John Roberts.

Burr’s trial was a spectacle. As part of his defense, Burr sought a subpoena against President Thomas Jefferson, demanding that Jefferson turn over documents he’d referred to in a message to Congress denouncing Burr. Jefferson resisted.

In a dramatic decision, Marshall ruled in favor of Burr’s subpoena. The president was not a king, Marshall explained. (Roberts seems to have relished quoting this language.) He was subject to the rule of law, and could be subpoenaed like anyone else. Jefferson agreed to send the documents, but not to appear in person in court. Marshall then rejected the prosecution’s theory of the case, and Burr was acquitted.

Roberts went on to explain that since the Burr trial, it has been accepted that the president can be subpoenaed. The culmination of this tradition was the Watergate tapes case, where the Supreme Court unanimously held that the president must turn over the tapes as part of a federal criminal trial. In that case, the court expressly balanced the president’s interests against those of the judicial branch of government, and found that the judicial need outweighed the president’s interests.

Since the Vance case involves state, not federal, criminal prosecution, Roberts had to address the differences. He concluded that the president would not be unduly burdened by responding to a criminal subpoena. Material submitted to a grand jury would be secret, he pointed out, protecting the president from potential embarrassment. And he said that he was not overly concerned about a president being harassed by state district attorneys.

Remarkably, Roberts did not conclude that the president must be given special protection compared to other citizens when it comes to answering a criminal subpoena about a personal matter, rather than an official presidential act. Rather, he concluded, the president would be restricted to the “protections available to every other citizen.”

Brett Kavanaugh, joined by Neil Gorsuch, agreed in principle that Trump's papers could be subpoenaed, but argued for a higher standard than would apply to an ordinary citizen. Clarence Thomas, joined by Samuel Alito, dissented, saying that although New York State could issue this subpoena, Trump should be immune from it if he could show that the job of the presidency required all of his attention.

Trump v. Mazars
This second, related decision was also written by Roberts. Here, the Supreme Court instructed the lower courts to reconsider whether the House of Representatives can subpoena Donald Trump's tax records. All four of the liberal justices joined Roberts's opinion, a sign that they think that there should be clearer guidance for the courts to draw lines protecting a president from embarrassing congressional fishing expeditions.

Perhaps most important, the decision appears not to have gutted Congress’s oversight powers, a result that seemed possible after the oral argument in the case.

Roberts framed the opinion by saying that the court had never before addressed the question of how far Congress could go in subpoenaing the president. Past conflicts between Congress and the president, Roberts explained, had been resolved through the give-and-take of the political process

In other words, precedent could not decide the issue — unlike in the Vance case.

The Trump administration argued that the case should be decided using a principle stated by the Supreme Court in the Watergate tapes case, in which the court said that Congress must show a “demonstrated, specific need” for the tapes of the Oval Office conversations. The Trump administration also argued that Congress must show that the material subpoenaed was “demonstrably critical” to a legitimate legislative purpose.

Roberts’s opinion rejected both of these standards as too demanding. Standards applicable to the private White House conversations of a sitting president must not be “transplanted root and branch” to a demand for “nonprivileged, private information” having nothing to do with the president’s performance of his official duties.

At the same time, Roberts also rejected the view that the subpoena could be treated like an ordinary congressional subpoena. A subpoena directed by Congress to the president, he reasoned, implicated fundamental questions about the separation of powers. Roberts expressed discomfort with the idea of leaving “essentially no limits on the congressional power to subpoena the president’s personal records.” It also clearly mattered to Roberts that the case itself grew out of the context of a necessarily partisan congressional investigation.

In the absence of precedent, Roberts chose pragmatism. He listed four factors that the courts should consider when weighing the legitimacy of a congressional subpoena of the president for his personal, nonprivileged records:

• First, courts should “carefully assess” whether the legislative purpose asserted by Congress really warrants the material being subpoenaed — or whether the information can be gotten some other way.
• Second, the subpoena should be “no broader than reasonably necessary.” The introduction of a standard of “reasonableness” is the signature trick of courts who do not want to impose bright-line rules, but rather want to give discretion to judges to apply flexible standards.
• Third, courts should pay attention to the justification that Congress offers for why the subpoenaed material meets a “valid legislative purpose.” Vague assertions would not do, Roberts intimated. “Detailed and substantial evidence” would be “better.” This formulation fell short of giving complete deference to Congress’s determination of what counts as a valid legislative purpose, as I personally would have preferred. But it also did not do damage by imposing an unreasonably high standard of evidence on Congress while engaged in its oversight function.
• Fourth, Roberts said that the court should consider carefully whether the president would be burdened by the subpoena. It would not be enough, Roberts said, for the president simply to say that he was busy.

Clarence Thomas dissented, arguing that Congress could only have subpoenaed the records under the impeachment power. Samuel Alito wrote a separate dissent; he would have held that subpoenas for the president’s personal documents “are inherently suspicious” because they are “seldom of any special value in considering potential legislation.”

Bottom line

My takeaway from Trump v. Vance is that the case brought together Roberts’s judicial philosophy with his new-found passion for subjecting Donald Trump to the rule of law. Precedent weighed in favor of allowing the subpoena, and precedent has been Roberts’s watchword this term.

But equally or more important was Roberts’s emergent self-understanding as the John Marshall of the moment, standing up to Trump as Marshall stood up to Jefferson. Marshall’s “declaration” (Roberts’s term) that the president is not a king runs across the centuries.

Roberts comes from a Republican background, and was made chief justice by the last Republican president before Trump. But he has seen Trump’s contempt for the rule of law, and he has made it his business to try and do something about it. History will treat the Vance decision kindly.

In Mazars, a case between Congress and the president, Roberts took a more cautious, nuanced tack — appropriately enough for a court being asked to intervene in a political dispute between the two other branches of government. The fact that the result was 7-2, not 5-4, can be counted as a victory for Roberts, who cares profoundly that the court not be seen as a partisan body.

Overall, we can look at these decisions as genuine accomplishments by the Supreme Court. Somehow, against the odds, the court is reestablishing its legitimacy, and pushing the specter of the partisanship of Bush v. Gore further into the past.

Noah Feldman is a Bloomberg Opinion columnist and host of the podcast “Deep Background.” He is a professor of law at Harvard University and was a clerk to U.S. Supreme Court Justice David Souter. His books include “The Three Lives of James Madison: Genius, Partisan, President.”