Trump's strategy of stonewalling Congress faced its first major legal test today, and the judge didn't let either side off the hook

• On Tuesday, President Donald Trump faced his first major legal test over whether he can continue his strategy of stonewalling Congress as it seeks to investigate his financial dealings and foreign ties.
• US District Court Judge Amit Mehta oversaw a hearing on whether the House Oversight Committee's subpoena of Trump's accounting firm, Mazars USA, for years of Trump's financial records is lawful.
• Lawyers representing Trump and several of his businesses argued that the committee's subpoena does not serve a legitimate legislative purpose and is therefore invalid.
• Lawyers representing the committee disagreed, saying the subpoena answers a legislative question because it seeks to uncover whether Trump violated the Ethics in Government Act and whether Congress needs to change the law.
• Mehta did not rule on the issue Tuesday but pushed back hard on both sides' arguments, indicating a drawn out fight ahead.
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President Donald Trump's strategy of stonewalling Congress at every turn as it seeks to investigate him faced its first major test judicial test on Tuesday.

US District Court Judge Amit Mehta presided over a hearing in Washington, DC, that weighed Congress' oversight powers against Trump's claims of personal privacy.

At the center of the legal battle is a subpoena the House Oversight Committee sent to Trump's accounting firm, Mazars USA, seeking several years of Trump's financial records. House Oversight Committee Chairman Rep. Elijah Cummings called it a "friendly subpoena" because Mazars USA had requested one from the committee before turning over records related to the president's finances.

In turn, Trump and several of his businesses sued Mazars USA, Cummings, and Peter Kenny, the chief investigative counsel for House oversight Democrats, to block the subpoena.

Mehta kicked off the hearing by announcing he would not rule on the issue Tuesday, saying it presented some "serious" questions. "No judge would make a hasty decision on such important issues for the sake of expediency," he said.

Still, the judge pushed both sides hard over the merits of their claims and didn't let either of them off the hook.

Read more: The Trump Organization sues the chairman of the House Oversight Committee to block subpoena of Trump's financial records

William Consovoy, an attorney representing Trump's interests, started things off by reiterating an argument the president's legal team made in its initial lawsuit and briefs: Congressional subpoenas that address a legislative purpose are valid, while subpoenas that serve a law enforcement or investigative purpose are not. Cummings' subpoena, according to Trump's lawyers, does not have a legislative purpose and is therefore invalid.

Consovoy also said Congress does not have the power to engage in law enforcement actions or investigations, which he said Cummings' subpoena amounted to. He also said the committee does not have the right to investigate Trump and then take legislative steps if it uncovers something inappropriate or criminal.

"That crosses a line," he said.

Meanwhile, Douglas Letter, the general counsel for the House of Representatives, argued that the subpoena answers a legislative purpose. Cummings has said he believes Trump may have violated the Ethics in Government Act, based on testimony and documents that Michael Cohen provided to the oversight committee in February.

Read more: White House officials asked Don McGahn to publicly say Trump didn't obstruct justice after they saw Mueller's report

Letter said that the law requires that the president release an annual financial disclosure form. If Trump is ignoring the law, Letter continued, then Congress may need to change it, which indicates that the subpoena serves a legislative purpose.

The defense counsel also pointed to the Presidential Records Act as an example of how Congress can regulate the executive branch. Letter said many former presidents destroyed records for years, but after former President Richard Nixon was forced to resign, Congress passed the Presidential Records Act to ensure the preservation of documents.

The subpoena 'really does open the door' to accusations that Democrats are meddling in Trump's private life 'for political purposes'

But Mehta pushed back at times on Letter's argument.

The subpoena "really does open the door, it seems to me, to the accusation that this really is sort of an effort, if not to harass the president ... then to get into his private affairs for political purposes," he said.

Read more: The FBI's former top lawyer said Mueller's obstruction findings are 'alarming' and show a 'pattern of corruption'

Consovoy also argued that Congress can't investigate Trump's financial records because he is not a federal agency.

"You mean to tell me that because he's the President of the United States, Congress has no authority to investigate?" Mehta shot back.

Mehta also wanted to know whether, in Consovoy's view, the Watergate investigation went beyond the scope of Congress' authority. Consovoy said he would "have to look at the basis."

Mehta responded that in the Watergate inquiry, Congress was investigating whether there were violations of criminal law, adding that "it was pretty straightforward."

Even so, Mehta added, it wasn't his place as a judge to look to Congress' motives.

Consovoy said he wasn't asking the court to look at Congress' motive, but instead to evaluate whether the point of the subpoena was legislative or related to law enforcement.

Read more: Trump just walked back his claim that there was 'no obstruction' in the Mueller probe in a big way

Later in the hearing, Mehta pressed Letter on whether there is "anything about the president's private life that you think is off limits to Congress."

Letter said asking for Trump's diary from when he was seven or 12 years old "would probably stretch my arguments to the breaking point." But he added that "we're nowhere near that today."

Conversely, Letter said, Congress would be authorized to examine whether Trump withdrew from the Trump International Hotel lease or if he's still benefiting from it financially.

But he emphasized that it's not Trump's place to question the scope of the Mazars USA subpoena. "That's for Congress and Congress alone to do," he added.

Perhaps one of the most interesting exchanges came near the end of the hearing, when Mehta asked Letter why Congress should be able to investigate whether the president committed crimes before taking office.

Letter replied that lawmakers "need to know if the President of the United States is beholden to foreign interests that can blackmail him."

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