It's been months since the House of Representatives subpoenaed former White House Counsel Don McGahn to testify.

McGahn played a key role in the Mueller Report, which laid out multiple instances of President Donald Trump asking McGahn—who represented the White House, not the President—to carry out illegal orders, which McGahn refused.

Like numerous other witnesses, the White House blocked McGahn from testifying before Congress.

Now, U.S. District Judge Ketanji Brown Jackson ruled that McGahn must testify, explaining to the White House's legal team that presidents are not, in fact, kings.

Judge Jackson wrote:

"Stated simply, the primary takeaway from the past 250 years of recorded American history is that Presidents are not kings. This means that they do not have subjects, bound by loyalty or blood, whose destiny they are entitled to control."

"Rather, in this land of liberty, it is indisputable that current and former employees of the White House work for the People of the United States, and that they take an oath to protect and defend the Constitution of the United States."

In addition to allowing McGahn's testimony, the finding that the White House can't bar close aides from testifying opens up the possibility for several Trump subpoenaed Trump aides to testify in the ongoing impeachment inquiry against him.

White House Press Secretary Stephanie Grisham is determined to appeal the decision, falsely asserting that the ruling:

"contradicts longstanding legal precedent established by administrations of both parties."

Grisham said:

"We will appeal and are confident that the important constitutional principle advanced by the administration will be vindicated."

You can read Judge Jackson's full ruling here.

The book How Trump Obstructed Justice (and Received Help from Russia): The Complete Report of Special Counsel Robert Mueller into Donald Trump's Collusion with Russia and Obstruction of Justice is available here.