The records sought traces of allegations of abuse before Trump became president, and the disputed subpoenas were given to accountants and banks, not directly to the president. Trump intervened to try to block subpoenas; he lost in the notices.
Justice is likely to spend much of its time arguing in the spine of the president's immunity and subpoena, but a fundamental question is raised: Is the president out of bounds?
Will the justice, especially Trump appointing Neil Gorsuch and Brett Kavanaugh, reveal sympathy or skepticism about core arguments to protect the president from scrutiny?
Challengers say Trump's position would put him "above the law."
Thinking of justice beyond Donald Trump?
Right now, a Republican is struggling with subpoenas from a Democrat-led House of Representatives. In the near future, the political players could be turned around.
With a choice on the horizon, will the attorneys' questions indicate concerns about the broader reverberations of limiting the House's power, or will they view the House's position under any circumstances as a "blank check" to pursue a president?
Much of the current controversy traces Trump's unique decision to keep ties to private business interests. Former presidents sold assets or used blind trust. House attorneys have argued that Trump's global economic interests have created distinct conflicts. Still, it is not difficult to imagine future clashes with different presidents in the congressional committee's view.
Is it in the middle between Trump and Congress?
Between the president and the House Democrats, justice can seek a certain middle ground. House attorneys claim the subpoenas issued to Trump's longtime accountants and banks are crucial to core legislative purposes when crafting new anti-corruption laws, and they say the court owes Congress disrespect to the legislative work.
Trump and his lawyers characterize the subpoenas are part of a fishing expedition in his private records, warning that if the house wins in these disputes, politically motivated subpoenas would be routinely enforced.
The Justice Department, more in line with Trump than the House, is trying to offer the court a midfield that would allow subpoenas, but set an "increased" standard for when justified. Departmental attorneys argue that any subpoena had to be approved by the entire house, not just by investigative committees that happened in these cases. They also insist that statutory purposes which are claimed must be particularly detailed and clearly relevant to the stated purpose. If the judges bite to an "increased" standard, the crucial question will be how precisely it is defined, and could the House ever satisfy it.
Will the judges try to avoid a verdict in the battle of the house altogether?
There is a chance that the judges will find that they find that the House Committee's controversy is too political for the judges to resolve.
Two weeks ago, the court asked the parties whether the court should avoid any decision because of the "political question doctrine or related principles of justice." This suggested that some justices believed the political nature of the case could prevent them from sentencing, and perhaps those justices could follow up with questions on Tuesday. Supreme Court judges found no such barriers to reach the merits of the constitutional dilemma, and both sides of the current dispute recently told the court that it has no grounds to opt out.
Admittedly, the justices can quietly wish they did not deal with the Trump House face in a presidential election year. But the cases mark a crucial constitutional test of Congressional oversight.
How far can justice go to favor Trump in a criminal investigation?
This extreme attitude associated with any criminal investigation extends the Justice Department's guidelines prohibiting prosecution against a president and conflicts with the Supreme Court precedent. Manhattan District Attorney Cyrus Vance counts that the grand jury wants routine material from Trump accountants and insists that such a third-party request would not interfere with his duties. (The request comes from a probe of so-called hush money paid to women during the 2016 presidential campaign who said they had issues with Trump.)
Still, there may be concerns among the prosecuting justice in 50 states that are investigating a president. The Justice Department has again offered a test that will favor the president, but not go as far as his lawyers want. It states that a prosecuting authority should show that the materials being searched were "essential" for an investigation.
Will Chief Roberts unite the bench?
An axiom of today's Supreme Court is that tough cases come down to Roberts, the conservative justice closest to the ideological center of the Nine. These three disputes constitute an even greater imperative for a judge who has clarified his concerns about the integrity of the court.
Will Roberts send any early signal Tuesday on the public-eye justice dilemma? He insists that justice does not govern as Republicans or Democrats, but "decides cases under the Constitution and laws without fear or favor."
Will he follow a narrow approach, against possible unanimity, or at least a result that avoids the 5-4 classic split that defines Roberts Court?