Former FBI Director James Comey’s explosive testimony before the Senate Intelligence Committee began with an unambiguous declaration that the president of the United States lied about his firing. He went on to raise serious questions about Trump’s efforts to impede an FBI investigation into possible collusion between Trump or his associates and the Russian government. These questions require immediate investigation by an independent commission free of Trump’s interference.

While there is much that requires further investigation, we cannot continue to stick our heads in the sand in avoidance of what is already known. Impeachment of an elected president is an act of enormous magnitude that must not be undertaken lightly or in response to routine political disagreements or policy differences. But the seriousness of the remedy speaks not only to the danger of its misuse, but to the importance of using it when appropriate. Our system depends on trust and goodwill. Breaking of norms and disregard for decency have huge, long-term costs. No one can be immune from our laws; everyone must be held to account. If Congress does not uphold that principle, it will have done more damage to our democracy than Russia could ever hope to.

The clear and undisputed facts about Mr. Trump’s attempt to impede an FBI investigation demand an immediate impeachment inquiry by the House of Representatives.

While running for office, the president of the United States publicly asked Russia to reveal his opponent’s email correspondence.

Russia successfully interfered in our presidential election with the intent of helping Trump, by hacking the computer systems of his opponent

The president’s closest associates, including his Attorney General, former National Security Adviser, and son-in-law have made false claims under oath during background checks and confirmation hearings about their contacts with agents of the Russian government

The president has said on national television that he fired the Director of the Federal Bureau of Investigation because of the FBI’s investigation of Russian electoral interference.

These facts are not in serious dispute — indeed, two of them are simply the president’s own televised words. Other recent revelations are similarly concerning:

Trump reportedly asked the Director of National Intelligence, in presence of the Director of the CIA, to impede the FBI investigation of National Security Adviser Michael Flynn, a close Trump associate who kept secret his contacts with Russia..

Former FBI Director James Comey has testified to the Senate Intelligence Committee that Trump requested his “loyalty” — a request House Speaker Paul Ryan acknowledges is an inappropriate threat to the FBI’s independence — and urged him to drop the Flynn investigation.

Trump reportedly told Russian officials that firing Comey had relieved “great pressure because of Russia.”

The facts that we know already exceed standards for presidential impeachment for obstruction of justice set in 1974 and 1998.

The first article of impeachment recommended by the House Judiciary Committee in 1974 stated that President Nixon, “in violation of his constitutional oath faithfully to execute the office of president of the United States and, to the best of his ability, preserve, protect, and defend the Constitution of the United States, and in violation of his constitutional duty to take care that the laws be faithfully executed, has prevented, obstructed, and impeded the administration of justice.” The Committee specifically accused Nixon of “interfering or endeavouring to interfere with the conduct of investigations by … the Federal Bureau of Investigation” and “endeavouring to misuse the Central Intelligence Agency.”

When House Republicans impeached President Bill Clinton in 1998, they cited his alleged obstruction of an investigation into a matter far less consequential than possible collaboration with a successful Russian attack of American democracy. One of two articles of impeachment passed by the House asserted that Clinton, “in violation of his constitutional duty to take care that the laws be faithfully executed, has prevented, obstructed, and impeded the administration of justice.” Explaining his support for Clinton’s impeachment, Virginia Rep. Bob Goodlatte said: “the president knowingly engaged in a calculated pattern of lies, deceit, and delay in order to mislead the American people [and] impede the search for truth.” Rep. Goodlatte now serves as chair of the House Judiciary Committee, which has responsibility for conducting impeachment hearings.

The facts we already know — facts that are not in dispute, including the president’s own televised statements — easily meet the standards for impeachment set by Congressional Republicans in 1998, many of whom are still in office.

The president of the United States has admitted firing an FBI Director over an investigation into Russian election interference on his behalf — the most serious foreign attack on American democracy since our nation’s founding. We must demand answers to many grave questions arising from this crisis, but the most urgent is this: How are Congressional Republicans going to hold to account a president whose efforts to obstruct an FBI investigation clearly meet the standards for impeachment articulated by Congressional Republicans fewer than twenty years ago?