Former House Judiciary Committee chairman John Conyers, the senior member of the House of Representatives and the only remaining member of the committee that approved Articles of Impeachment against President Nixon in 1974, responded with necessary perspective and clarity to President Trump’s decision Tuesday to fire FBI director James Comey.

“Today’s action by President Trump completely obliterates any semblance of an independent investigation into Russian efforts to influence our election, and places our nation on the verge of a constitutional crisis,” said the Democratic congressman from Michigan, who did not hesitate to draw a comparison between Trump’s firing of Comey, who was overseeing an inquiry into Trump campaign wrongdoing, with Nixon’s Watergate-era machinations to force the removal of the special prosecutor, who was investigating his high crimes and misdemeanors.

“There is little doubt that the President’s actions harken our nation back to Watergate and the ‘Saturday Night Massacre,’” asserted Conyers. “This decision makes it clear that we must have an independent, non-partisan commission to investigate both Russian interference in the U.S. election and allegations of collusion between the government of Vladimir Putin and the Trump campaign. Today’s actions reek of a cover up and appear to be part of an ongoing effort by the Trump White House to impede the investigation into Russian ties and interference in our elections.”

All true.

But then Conyers focused on the role that Attorney General Jeff Sessions played in facilitating the firing of Comey. “I am particularly concerned that President Trump fired Director Comey based in part on the recommendation of Attorney General Sessions–who was forced to recuse himself from the underlying investigation based on his own actions and misconduct,” said Conyers. “This shocking decision by the President is beyond the pale and itself warrants independent inquiry and hearings, and reinforces the need for the Attorney General himself to step down given his own obvious and ongoing conflicts.”

Sessions should step down. Immediately.

If he fails to do so, then members of the House, Democrats and Republicans, must move to impeach the attorney general. And members of the Senate, Democrats and Republicans, must recognize the need to remove Sessions from the position he obtained after deceiving the Senate Judiciary Committee about what John Conyers correctly identifies as “misconduct.”

This is not the only appropriate and necessary response to the firing of Comey, which Congressman Jerrold Nadler, the former chair and ranking member of the House Judiciary Subcommittee on the Constitution, says has the United States “careening towards a constitutional crisis.” Nadler warns that “the Administration (is) systematically attacking all of the institutions that are meant to put a check on the power of the President.”

Minnesota Congressman Keith Ellison, a lawyer and former Judiciary Committee member, says, “The next FBI Director appointed by President Trump will not have the independence or confidence of the American people to continue this investigation. In order to preserve the integrity of the investigation and the government, we need a special prosecutor to probe the possible collusion between Donald Trump’s campaign and Russian government officials.”

The urgent calls by dozens of members of Congress for a special prosecutor or a special commission (an option being explored by Michigan Republican Congressman Justin Amash) reveal the extent to which Sessions has destroyed the credibility of the Department of Justice when it comes to the inquiry. The fact that Sessions refuses to recognize his own role in this crisis is more than concerning. It is disqualifying.

Sessions formally recommended the Comey firing—claiming that a fresh report had suddenly caused him to be concerned about how the FBI director treated Hillary Clinton during last year’s presidential campaign. Coming from the hyper-partisan and fiercely ideological Sessions, that’s laughable. “The President’s firing of FBI Director James Comey is akin to Nixon’s Saturday Night Massacre during the Watergate scandal, and shows that the President is willing to go to any length to hold himself above the law,” says Congresswoman Jackie Speier, a California Democrat who serves on the House Permanent Select Committee on Intelligence. “If Mr. Comey did indeed uncover information of the President’s Russian entanglements, firing him gives the appearance of an enormous cover-up. The Administration and the Attorney General’s pretense that this is about the investigation into Hillary Clinton’s emails is a laughable fig leaf, particularly since AG Sessions himself had to recuse himself from the Russia investigation.”

The backstory on the Sessions recusal points to why the attorney general must now be held to account.

In early March, The Washington Post revealed that during the 2016 presidential campaign, when Sessions was a close counselor and top surrogate for Donald Trump, he spoke twice with Russia’s ambassador to the United States. Sessions acknowledged the meetings following the Post report. But when he appeared before the Senate Judiciary Committee as Trump’s nominee for attorney general in January, he failed to do so.

House Minority Leader Nancy Pelosi said at the time that “Jeff Sessions lied under oath.” And it was hard to argue with her conclusion.

Minnesota Senator Al Franken asked how Sessions might handle revelations that individuals associated with the Trump campaign had communicated with the Russian government. Sessions replied, “I’m not aware of any of those activities. I have been called a surrogate at a time or two in that campaign and I did not have communications with the Russians.”

This was not the only denial from Sessions. According to the Post, in January Senator Patrick Leahy, D-Vermont, asked Sessions for answers to written questions. “Several of the President-elect’s nominees or senior advisers have Russian ties. Have you been in contact with anyone connected to any part of the Russian government about the 2016 election, either before or after election day?” Leahy wrote. Sessions responded with one word: “No.”

Unless we imagine that Sessions is far too absentminded to continue to serve as attorney general (a circumstance that no one seriously entertains), then there can be no question that this man engaged in a blatant attempt to deceive the very Senate that was charged with determining whether he would take charge of the Department of Justice.

Despite that fact, Sessions avoided accountability by announcing that he was recusing himself from any examination of Russian involvement with President Trump’s campaign.

Now Sessions has violated his own recusal, in what Franken characterizes as “a complete betrayal of his commitment to the public that he wouldn’t be involved in the investigation.” This should be the last straw.

Sessions refuses to recognize, or to take responsibility for, his wrongdoing. Indeed, by playing a central role in the process that led to the firing of FBI director Comey, the attorney general has decided to perpetuate that wrongdoing. This is a deeply unsettling development that calls into question every action of the Department of Justice that Sessions continues to lead.

But the Constitution offers a remedy. Article II, Section 4 of the founding document explains that “The President, Vice President and all civil Officers of the United States, shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors.” The attorney general is a civil officer of the United States.

In March, as Congressman Conyers notes, Attorney General Sessions was “forced to recuse himself from the underlying investigation based on his own actions and misconduct.”

Now Attorney General Sessions has abandoned the accountability standard he set for himself. There can be no more excuses. Sessions has a duty to resign. If he refuses to recognize and act upon that duty, then he must be impeached.