Asked at the close of the Constitutional Convention of 1787 if the delegates had created a republic or a monarchy, Benjamin Franklin is reported to have replied, “A republic, if you can keep it.”

Paul Ryan has abandoned the effort to keep it.

At the heart of the US Constitution is a system of checks and balances that was established primarily to guard against the concentration of power in an executive branch that might tend toward royalism. The founders of the American experiment wanted to prevent a repeat of the monarchical abuses of King George III, against which their constituents had risen in revolution.

“The accumulation of all powers, legislative, executive, and judiciary, in the same hands, whether of one, a few, or many, and whether hereditary, selfappointed, or elective, may justly be pronounced the very definition of tyranny,” warned James Madison, the essential author of the Constitution, who explained, “The great security against a gradual concentration of the several powers in the same department, consists in giving to those who administer each department the necessary constitutional means and personal motives to resist encroachments of the others.”

What Madison asserted in the late 1780s remains true to this day: For the system of checks and balances to function, the leaders charged with responsibility for the various branches of government must zealously defend the authority of the branches they lead. They cannot allow one branch to become the extension of another.

This is the basic duty that House Speaker Paul Ryan rejected when he chose to make the legislative chamber subservient to President Trump’s lawless executive branch. Ryan’s abandonment of the Constitution began long ago. But it culminated with the speaker’s decision to support Friday’s release of a partisan memo produced by disgraced House Permanent Select Committee on Intelligence chair Devin Nunes (R-CA) to discredit law-enforcement agencies that have organized and supported inquiries into Trump-campaign and Trump-administration wrongdoing.

“Discrediting law enforcement is the memo’s transparent purpose and why it has been embraced by President Trump,” argued a Washington Post editorial that condemned Ryan’s choice. “Written mainly by the staff of Devin Nunes (R-CA), the loose-cannon chairman of the House Permanent Select Committee on Intelligence, the memo reportedly makes the case that the FBI abused spying authorities as it sought permission to surveil a former Trump adviser,” noted the Post. “The Justice Department called its potential release, which Mr. Trump reportedly intends to approve, ‘extraordinarily reckless.’ The FBI released its own startling public statement citing ‘grave concerns about material omissions of fact that fundamentally impact the memo’s accuracy.’ Adam Schiff (D-CA), the ranking Democrat on the Intelligence Committee, wrote in a Post op-ed that the Nunes memo ‘cherry-picks facts, ignores others and smears the FBI and the Justice Department.’”

The Post’s editorial appeared just before the release of the memo. But the concerns it expressed were confirmed by the document, which makes over-the-top and highly speculative allegations about how the inquiry into the Trump team’s Russia ties has been conducted, and especially about how FISA warrants were obtained, but fails to present an even minimally credible case that the inquiry is unnecessary or inappropriate.

That memo is so thin in content and character that it adds weight to the argument made by the Post with a headline that read: “Paul Ryan is tarnishing the House.”

The speaker’s embrace of Nunes and his memo has dishonored the chamber that he, above all others, is duty bound to defend.

But that is the least of the sins against the American experiment committed by Ryan in collaboration with Nunes. Illinois Congressman Mike Quigley, a key Democrat on the Intelligence Committee, aptly describes Ryan and Nunes as “co-conspirators” in doing the bidding of a president who has “freaked out” over special counsel Robert Mueller’s investigation into Russian meddling in the 2016 presidential election.

Nunes is a secondary figure, whom Quigley appropriately dismisses as nothing more than an agent for Trump.

Ryan’s dereliction of duty is the more serious matter, as it betrays the most fundamental tenets of the Constitution. When the speaker chose to facilitate this bungling effort by Nunes to smear the Federal Bureau of Investigation and the Department of Justice on Trump’s behalf, the Wisconsin Republican signaled a willingness to make the House of Representatives an appendage of the White House.

In so doing, Ryan abandoned the solemn oath he swore “to support and defend the Constitution of the United States against all enemies, foreign and domestic…”

Paul Ryan is not supporting the Constitution. He is shredding it. It is grotesque for the speaker to claim that he is aiding and abetting Nunes because “that brings us accountability, that brings us transparency, that helps us clean up any problem we have with [the Justice Department] and FBI”—as Ryan did Thursday in a crudely defensive and wildly dishonest attempt to deny his true intentions.

Make no mistake: Paul Ryan has zero interest in accountability, transparency, or cleaning up problems with law-enforcement agencies and the investigative process. He has shown no interest in legitimate and necessary oversight of intelligence agencies. He has never been identified with the cause of civil liberties or with the defense of privacy rights.

What Paul Ryan has been identified with is extreme partisanship and with the determination of congressional Republicans to defend Donald Trump—even if that defense comes at the cost of a system of checks and balances that was established 231 years ago to guard against precisely the abuses that are now occurring.