House Democrats defended their congressional investigations in two different federal courtrooms on Thursday afternoon in Washington, in separation-of-powers fights about subpoenas at the heart of the impeachment drama.

First, the House Judiciary Committee pushed to enforce its subpoena of ex-White House Counsel Don McGahn to testify about what he told former Special Counsel Robert S. Mueller III’s probe into potential obstruction of justice by President Donald Trump.

[House Democrats adopt rules for public impeachment proceedings]

And two hours later, down the hall, the House Intelligence Committee told a judge it would seek to dismiss a lawsuit filed by former National Security Council official Charles Kupperman, which asks the courts to decide whether he must comply with a subpoena in an impeachment inquiry focused on Trump’s dealings with Ukraine.

The high-profile hearings didn’t provide definitive answers Thursday, but shed some light on whether the courts will act quickly enough to influence the House Democrats’ fast-moving impeachment inquiry.

In the Kupperman case, U.S. District Senior Judge Richard J. Leon set oral argument for Dec. 10, a relatively speedy schedule for what he called a matter of great importance to the country. He indicated he wanted to rule by late December or early January.

Leon even declined a request from a Justice Department lawyer for some relief from a briefing deadline right after Thanksgiving weekend. In a case of this importance, you “roll up your sleeves and get the job done,” the judge said.

The House approved an impeachment resolution Thursday morning to establish rules for how it will make its public case ahead of the political season next year.

House Democrats already have said they expect their impeachment probe to outpace ongoing court cases once seen as critical to the impeachment inquiry, including the McGahn subpoena.

Intelligence Chairman Adam B. Schiff, D-Calif., said after Kupperman did not appear for closed-door testimony Monday that Democrats won’t engage in a lengthy court battle with the administration over witnesses.

“We are not willing to allow the White House to engage us in a lengthy game of rope-a-dope,” Schiff said.

Todd Tatelman, deputy House general counsel, told Leon that lawmakers “believe this complaint serves no other purpose than to delay” the congressional right to investigate.

Cooper also represents former National Security Advisor John Bolton, who has been invited to testify but not been subpoenaed. Under questioning from Leon, Cooper said that there would be no need to extend the court schedule because the issues would be the same.

Leon set a status hearing in the Kupperman lawsuit Thursday, less than a week after it was filed, “due to the time-sensitive nature of the issues raised in this case.”

Leon, who served as counsel to Congress in the investigations of three sitting presidents, has co-taught a course on congressional investigations at Georgetown University Law Center since 1997, according to his teaching biography.

The McGahn and Kupperman cases ultimately could set new precedents for the extent of congressional power to compel testimony from executive branch officials.

Schiff has been leading closed-door depositions with witnesses about whether Trump withheld military aid for Ukraine to pressure that country to investigate former Vice President Joseph R. Biden Jr., one of Trump’s main political rivals. Some witnesses are eventually expected to testify publicly before the Intelligence Committee.

While the focus of the impeachment inquiry has moved to Trump’s dealings with Ukraine, some House Democrats consider the McGahn case the key test of congressional subpoena power for other ongoing investigations.

The case is the first lawsuit House Democrats filed to force a Trump administration official to testify since Trump announced a fight-all-the-subpoenas strategy.

Judge Ketanji Brown Jackson, at the end of a nearly four hours of arguments in the McGahn case where she frequently challenged the Justice Department’s arguments, said that she would be ruling at a later date.

“You can rest assured I understand the significance of all of this and I will do my best to turn it around as soon as possible,” Jackson said.

The Judiciary Committee says the Mueller report on Russian interference in the 2016 election mentions McGahn’s statements 160 times in the section that focuses on whether Trump tried to obstruct the investigation.

And they argue he can give lawmakers a firsthand account of his discussions with Trump and other White House aides about the president’s actions and their reactions to them.

McGahn’s lawyers argue that he is “absolutely immune” from compelled testimony about his official duties as counsel to Trump, because confidential advice is essential to a president’s effective performance.

Both sides in McGahn’s case now agree on this: They are unlikely to reach an accommodation for his testimony and need the courts to decide.

Federal courts recently have backed congressional investigations. A district court judge backed the Judiciary Committee’s request for usually secret grand jury materials from the Mueller probe.

And an appeals court in Washington ruled that accounting firm Mazars USA can comply with a House Oversight and Reform Committee subpoena to turn over eight years of Trump’s financial records.