This seems to be the moment when the Mueller investigation and President Trump's impeachment inquiry finally connect.

After months of legal debate, the U.S. District Court for the District of Columbia ruled that former White House counsel, Donald F. McGahn II, should testify before House committees and give his account of the facts that led to alleged obstruction of justice by President Donald Trump during the investigation of special attorney Robert Mueller.

For those who have lost track of events in the country's political chaos, the nearly two-year special investigation conducted by special lawyer Robert Mueller exposed in 448 pages the digital attack and media campaign orchestrated by Moscow during the 2016 elections in favor of Donald Trump's campaign.

However, after 199 criminal charges and 37 accusations, the detailed investigation report repeatedly mentioned the then-White House counsel Don McGahn as a key witness in President Trump's attempts to shut down the investigation.

Obstruction by the administration, backed by the Department of Justice, prevented McGahn or any government official from appearing before House Committees, arguing "absolute immunity" within the executive branch.

The House Judiciary Committee took the case to court last August to "enforce McGahn's subpoena," according to the New York Times, and District Judge Ketanji Brown Jackson's response has become a moral lesson for the government, the Republican party, and the entire country.

Jackson exposed in more than 100 pages not only the legal framework that dismisses an "expansive authority" of the president, but also the risk that the perpetuation of such legal positions poses to the Constitution and, therefore, to the country's democracy.

“When DOJ insists that Presidents can lawfully prevent their senior-level aides from responding to compelled congressional process and that neither the federal courts nor Congress has the power to do anything about it, DOJ promotes a conception of separation-of-powers principles that gets these constitutional commands exactly backward,” the judge wrote.

“In reality, it is a core tenet of this Nation’s founding that the powers of a monarch must be split between the branches of the government to prevent tyranny,” she added.

Jackson notes with concern that "what's at stake" is the alleged impediment - say, obstruction - of government to allowing the natural and fair course of investigations that underpin the system of checks and balances, and the separation of powers among the branches of government.

Dismantling the alleged "immunity" of members of the government, the judge also warns of the risk of “the President purported power to kneecap” the investigations and obstructing the legal duty of citizens.

"Stated simply,” Jackson concludes, "the primary takeaway from the past 250 years of recorded American history is that Presidents are not kings.”

Jackson's decision then sets a critical legal precedent for the ongoing impeachment investigations against President Trump.

Since the Speaker of the House of Representatives declared the commencement of impeachment proceedings against the President, the White House has again resorted to the now-dismantled argument of "absolute immunity," refusing to allow its officials to appear before committees and withholding documentation fundamental to the process.

This new ruling gives Democrats sufficient legal reasoning to hold the government accountable and to make it clear that no one is above the law.