Bigger issues are at play, too.

Any Supreme Court ruling on these cases could define the contours of executive branch power for Trump and his successors, setting precedents on heated questions such as whether a sitting president can be criminally investigated and when the White House can resist a congressional subpoena. It could also offer some clarity to the Constitution’s vague and largely untested emoluments clause, which bars federal officials from receiving payments from foreign governments.

Most important is a traditional January deadline that looms for securing a coveted spot on the Supreme Court’s April calendar, which comes with the prospect of a decision in late June, well before voters go to the polls. Any case it doesn’t take for this term is highly unlikely to be decided before next November’s election.

Here’s a look at the court cases and where they stack up with respect to potential Supreme Court review.

Impeachment witnesses

Who has the ultimate power to get witnesses to talk — or to keep them quiet?

That’s the question at the heart of a court battle stemming from the House’s impeachment inquiry. Lawmakers are looking at whether Trump pressured Ukraine to launch politically advantageous probes and has subpoenaed a slate of current and former White House officials involved in those efforts.

But the White House has issued a blanket, do-not-comply order to anyone who ever worked in the administration, leaving potential congressional witnesses in a tough spot: Do they follow the boss or risk the legal ramifications of being a no-show on Capitol Hill?

In an effort to get clarity, Trump adviser Charles Kupperman last month went to the courts to request a ruling on the matter. Should he comply with the House subpoena or the White House no-show directive?

District Judge Richard Leon, appointed by President George W. Bush, set a Dec. 10 hearing in the case and indicated he’d like to rule by late December or early January.

There’s an added wrinkle. Kupperman shares a lawyer with his former boss, John Bolton, the former Trump national security adviser who is also expected to get a congressional subpoena to discuss the Ukraine affair. During a preliminary hearing on the Kupperman case last week, the attorney for both men acknowledged Bolton could soon join the case.

Any appeals of Leon’s decision could drag things out even more. And even if the courts require the Trump advisers to appear, there could be future rounds of litigation over what questions they can be forced to answer. All in all, the prospects look slim that Kupperman’s case could make it through the gantlet of steps necessary to secure a full Supreme Court review before Capitol Hill has exhausted its impeachment efforts, which may only last a few more months.

But an ultimate ruling could have long-tail ramifications as House Democrats continue to badger the president with investigations until Election Day.

“I just hope for the balance of power that there’s a recognition of congressional prerogatives on some of these issues,” said Ryan Goodman, a New York University law professor and co-editor-in-chief of the blog Just Security. “That’s what seems a real threat, that the stonewalling is backed up by legal edifice.”

Trump’s tax returns … and more

Trump’s financial records are the white whale for the president’s most vocal critics. And the Supreme Court could help them end their yearslong hunt.

If there’s one case most primed for a Supreme Court hearing next spring, it’s the one involving Manhattan District Attorney Cyrus Vance’s subpoena seeking eight years of Trump’s tax and financial records. Vance made the demand as part of his probe into hush-money payments made to adult film actress Stormy Daniels.

Trump fought the subpoena and lost, sending the case on appeal to the 2nd U.S. Circuit Court of Appeals in New York. Judges there put the case on an expedited schedule, hearing arguments just two weeks after Trump’s appeal.

That’s when the president’s lawyers made the headline-grabbing contention that their client couldn’t be arrested or charged by local authorities if he shot someone on Fifth Avenue — at least until he’s no longer president.

Before the hearing, Trump’s lawyers reached an agreement with Vance pledging that if they lose their appeal, Vance would give them 10 days to petition the Supreme Court for arguments during the current term.

Jay Sekulow, the longest-serving member of the president’s personal legal team, said the Vance case looked to him like the first one in line for Supreme Court review. It’s not an opinion everyone shares.

“The Supreme Court won’t be in any hurry to go out of the way,” University of Texas law professor Stephen Vladeck said.

Another pressing case involving Trump financial records resides in the U.S. Court of Appeals for the D.C. Circuit. That’s where the House Oversight and Reform Committee won an initial opinion backing its bid for the documents. The ruling even cited a Watergate-era precedent that “strongly implies that Presidents enjoy no blanket immunity from congressional subpoenas.”

Trump’s attorneys are trying to put a hold on the court order until they can get a rehearing before the entire D.C. Circuit, which is composed of seven active judges appointed by Democratic presidents and four by Republican presidents. Democrats have blasted the move as a stalling tactic. On Friday, House lawyers urged the appellate court to ignore Trump’s “inappropriate” request for a full panel review and instead let its earlier opinion stand, thereby requiring the financial documents be turned over to Democratic investigators.

There are two other notable lawsuits involving Trump’s tax returns, though they are further back in the process.

In one case in Washington, House Ways and Means Chairman Richard Neal (D-Mass.) is seeking a court order to enforce a subpoena to get Trump’s taxes from the Internal Revenue Service. Trump and the Treasury Department are trying to get the case dismissed. Arguments are scheduled for Wednesday, with District Judge Trevor McFadden, a 2017 Trump appointee, presiding.

House Ways and Means Committee Chairman Richard Neal. | Alex Brandon/AP Photo

The other case comes from Trump, who is suing Neal to prevent him from tapping into a New York law enacted in July that gives Congress the opportunity to obtain the president’s state tax returns. The lawsuit has gotten bogged down in a jurisdictional dispute over whether it should be heard in Washington, where Trump filed it, or in New York.

Another Trump appointee, Judge Carl Nichols, heard preliminary arguments in the case in mid-September, his first major case since taking a lifetime seat on the bench. Lawyers involved in the case have deadlines this month and in December to file briefs on Democrats’ motion to dismiss the case.

The ghosts of Robert Mueller

Yes, the Russia probe is not gone just yet.

Cases born out of the multiyear investigation into 2016 election interference will keep on making headlines throughout the 2020 campaign. They could deliver Mueller’s underlying evidence to lawmakers, shed light on what really happened with WikiLeaks and Trump’s campaign and, perhaps most importantly, force the former special counsel’s star witness to tell Congress about the president’s attempts to obstruct the Russia probe.

First in line is the court battle over the secret grand jury evidence that underpinned Mueller’s final report.

House Democrats scored a major win in October when District Judge Beryl Howell ruled their impeachment inquiry gave them the right to see select materials underlying the special counsel’s work.

But their victory remains on ice while the Trump administration appeals the ruling to the D.C. Circuit. It’s unclear how long the judges will take to consider whether to let Congress peek at the Mueller materials, but a Trump loss at the appeals court might take the case past the typical timeline for getting on the Supreme Court’s docket this term. In a filing Friday, House lawyers pleaded with the appellate court to let the district court ruling stand and remove an administrative stay blocking their access to the grand jury items.

“The public interest would be irreparably harmed if DOJ succeeds in running out the clock on impeachment through obstruction and delay," Douglas Letter, the House general counsel, wrote in the court brief.

Vladeck said DOJ appears unlikely to succeed in the appellate court but can still take its time in pressing for additional judicial scrutiny on the case. “It’s not hard to imagine [Trump] losing and slow-walking to the Supreme Court,” he said.

Then there’s Mueller key witness: former White House counsel Don McGahn.

House Democrats filed suit in August seeking McGahn’s testimony, weeks before the revelations about Trump’s pressure campaign on Ukraine. But lawmakers still want to hear from the man who showed up more than 500 times in Mueller’s final report, often giving firsthand accounts of the president’s alleged attempts to stymie or outright quash the Russia probe.

A federal judge said Thursday she would try to render a decision in the case in a matter of weeks.The judge seemed skeptical of the Justice Department’s argument that current and former senior White House aides have “absolute immunity” to ignore a subpoena from Congress.

Former White House counsel Don McGahn. | Saul Loeb/Pool Photo via AP

Other Mueller reminders are also looming in the legal system.

Longtime Trump associate Roger Stone goes on trial starting Tuesday in Washington. He faces charges of lying to Congress and obstructing the House Intelligence Committee’s Russia probe. The trial is expected to last three weeks and include a number of high-profile witnesses, including former Trump White House senior strategist Steve Bannon. During the 2016 campaign, Bannon was in contact with Stone, who suggested he had information about WikiLeaks’ plans to release damaging information about Hillary Clinton.

Trump also told Mueller’s team in written answers that he spoke to Stone “from time to time during the campaign.” The content of those conversations could be illuminating if they come up at the trial.

Two other former Trump aides who pleaded guilty during the Mueller probe have yet to be sentenced.

One is Rick Gates, a former 2016 deputy campaign chairman who has been a central witness in multiple cases brought by the special counsel’s team.

Gates has been a willing witness for the government, testifying in August 2018 against his longtime boss and former Trump campaign chairman Paul Manafort. His testimony helped prosecutors secure the 7½-year prison sentence Manafort received for a series of tax, bank fraud, lobbying and witness tampering convictions.

Gates still doesn't have a sentencing date set for his long-running case. Meantime, he also may be called as a government witness during the Stone trial.

The other former Trump aide awaiting his fate is Michael Flynn, who pleaded guilty in late 2017 to lying to the FBI about his contacts with Russia’s ambassador to the United States.

There is a tentative Dec. 18 date for Flynn’s sentencing, though the case has taken a strange twist after Trump’s first national security adviser hired a combative new attorney who is trying to get the entire case dismissed over what she claims is “egregious government misconduct.” The complaints from the lawyer, Sidney Powell, are widely seen as part of a push for a Trump pardon.

Mueller’s other outstanding prosecution — against a Russian firm charged with interfering in the 2016 presidential election — is still on track for an April 2020 trial.

The firm, Concord Management and Consulting, is fighting claims it financed and organized an army of online trolls who sowed discord in the U.S. to bolster Trump during the 2016 election. A federal judge has said she intends to rule by the end of the year on Concord’s motions to dismiss the case.

Emoluments

It’s the one issue that has dogged Trump since before his inauguration — whether the hotels and other hospitality businesses he owned could put him in the legal crosshairs.

At issue: the Constitution’s emoluments clauses, which forbid U.S. government employees from taking payments or gifts from state governments, foreign nations and state-owned companies.

The issue popped up recently when Trump announced plans to host the 2020 G-7 summit at his Doral resort near Miami. The move sparked a bipartisan outcry, and Trump made a rare reversal. But he’s still facing emoluments challenges over his signature hotel in Washington, even as he considers selling the rights for the property.

Historically, the emoluments clause has gone largely unchallenged in the court system. That means this series of emoluments-related cases will give judges the chance to rule on whether the clauses are essentially “phony,” as Trump calls them, or whether they have serious legal heft.

Three federal appellate courts are involved in lawsuits challenging Trump’s foreign business arrangements.

In the D.C. Circuit, oral arguments are scheduled for Dec. 9 in a case filed by more than 200 members of Congress, seeking the right to review any foreign payments, benefits or gifts to the president.

Three days later, on Dec. 12, the full 4th U.S. Circuit Court of Appeals will hear a case brought by Washington, D.C., and Maryland, alleging the Trump International Hotel in Washington is ground zero for emolument clause violations. A three-judge panel in July dismissed the case as fatally flawed, saying they had no legal right to enforce those constitutional provisions, but Washington and Maryland are hoping to get a more favorable hearing from the full court.

Trump International Hotel in Washington, D.C. | Mark Tenally/AP Photo

In another case, the Justice Department is trying to get the full 2nd Circuit to review an emoluments case filed by a government watchdog group and a collection of hotel and restaurant owners who said they were losing out on business because customers were flocking to Trump’s Washington hotel to curry favor with the president. The suit was revived in September with a 2nd Circuit ruling after another judge had dismissed the lawsuit in December 2017.

Legal experts are torn over whether the Supreme Court will jump into the emoluments dispute.

Philip Allen Lacovara, a former counsel to the lead Watergate prosecutor, said the issue is ripe for review because “there’s a plausible argument that Trump is essentially acting corruptly.”

But Alan Dershowitz, a retired Harvard law professor who has frequently defended Trump on cable television, countered that the issue isn’t the kind of topic the Supreme Court prefers to tackle.

“It’s not a crime. It’s not defined. It’s very open ended and broad,” he said.