WASHINGTON – President Trump lost a preliminary round Monday in his court battle with House Democrats, when a federal judge ruled his accounting firm must obey a subpoena to provide his financial records to Congress.

Trump called the 41-page ruling by U.S. District Judge Amit P. Mehta “crazy” and said he planned to appeal.

“We think it’s totally the wrong decision by, obviously, an Obama-appointed judge,” he said.

Trump is fighting a lengthening line of subpoenas for documents, financial records and witnesses, including testimony from Donald McGahn, his former White House counsel, who was ordered not to appear before a House committee to answer questions about his conversations with the president.

Judge Mehta summarily rejected arguments by Trump’s lawyers that the House Oversight Committee’s demands for records from the president’s accounting firm were needlessly broad and did not deal with any real legislative function.

“It is simply not fathomable that a Constitution that grants Congress the power to remove a president for reasons including criminal behavior would deny Congress the power to investigate him for unlawful conduct – past or present – even without formally opening an impeachment inquiry,” Mehta wrote.

Trump’s attorneys argue that presidents are protected by “executive privilege” in their dealings with advisers and other officials in the executive branch of government, and thus are beyond the reach of congressional investigations.

That is not the view of Judge Mehta and many other Constitutional scholars.

“Congress plainly views itself as having sweeping authority to investigate illegal conduct of a president, before and after taking office,” Mehta wrote. “This court is not prepared to roll back the tide of history.”

Perhaps no single witness being blocked by the Trump administration is more critically important than McGahn, whose testimony in special counsel Robert Mueller’s final report raises several instances of obstruction of justice by the president.

Notably, Judge Mehta’s Monday ruling against Trump came just hours after McGahn was told by the Department of Justice not to testify before Congress on Tuesday.

“The Department of Justice has provided a legal opinion stating that, based on long-standing, bipartisan and constitutional precedent, the former counsel to the president cannot be forced to give such testimony, and Mr. McGahn has been directed to act accordingly,” White House press secretary Sarah Sanders said in a statement.

“This action has been taken in order to ensure that future presidents can effectively execute the responsibilities of the office of the presidency,” Sanders said.

The 15-page Justice legal opinion was written by Assistant Attorney General Steven Engel.

House Democratic leaders weren’t buying the Justice Department’s hocus-pocus explanation.

“It is absurd for President Trump to claim privilege as to this witness’s testimony when that testimony was already described publicly in the Mueller report,” House Judiciary Committee Chairman Jerrold Nadler of New York said in a statement.

“Even more ridiculous is the extension of the privilege to cover events before and after Mr. McGahn’s service in the White House,” Nadler added.

Of course, when Nadler gaveled Tuesday’s hearing to be in session, McGahn was not in the witness chair. But his stunning testimony was in Mueller’s final report for all to see, saying that Trump asked him to fire Mueller.

A furious Nadler declared that “McGahn would be held in contempt for failing to appear,” The Associated Press reported. But “that’s not expected until June, after lawmakers return from the Memorial Day recess.” 

“Our subpoenas are not optional,” he said. “We will not allow the president to stop this investigation.”

“A short time later ... Nadler issued subpoenas for more Trump officials – former White House communications director Hope Hicks and Annie Donaldson, a former aide in the White House counsel’s office – for documents and testimony,” the AP said.

More witnesses will be called as the hearings continue through the spring. Expect some big surprises in the next few months.