Congress must draw 'red line' to protect Mueller, warn Trump against firing and pardons: Mark Warner We must make clear to Trump that firing Mueller or pardoning his witnesses will bring severe consequences, and call out our congressional colleagues who put party over truth.

Mark Warner | USA TODAY

Show Caption Hide Caption Andrew McCabe may have memos of Trump interactions Former FBI deputy director Andrew McCabe reportedly kept memos regarding President Donald Trump.

In 2016, Russia used the weapons of information warfare to attack the United States. The Kremlin’s goal: to undermine our democracy and weaken the United States and our Western democratic allies.

This is not the opinion of one senator, or of one political party. It is the unanimous conclusion of our nation’s intelligence community.

With his most recent indictment of 13 Russian operatives and three Russian companies, special counsel Robert Mueller further illuminated the depths of Russia’s information warfare campaign against the United States. Last month’s filing followed indictments and/or guilty pleas from several of President Trump's onetime associates — including campaign chairman Paul Manafort, top campaign aide Rick Gates, campaign foreign policy adviser George Papadopoulos and former national security adviser Michael Flynn.

Yet despite this effort to expose our Russian enemies and bring them to justice, Mueller now sits squarely in the crosshairs of Trump and his allies.

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Earlier this year, we learned how close our nation came to an extraordinary abuse of presidential power when it was revealed that President Trump ordered Mueller’s firing last June. He reportedly backed off only when White House counsel Don McGahn threatened to resign rather than carry out the corrupt order.

On Saturday, the president’s own lawyer, John Dowd, resurfaced this dangerous prospect when he called for the Mueller probe to be shut down. He said that was his personal opinion, but Trump quickly made clear that is his opinion, too.

"The Mueller probe should never have been started in that there was no collusion and there was no crime," the president tweeted Saturday evening, calling it a "witch hunt." He continued his attack Sunday morning with a tweet branding the investigation partisan and unfair.

Unfortunately, these are only the latest chapters in a seemingly coordinated effort to undermine not only Mueller, but also the career law enforcement and intelligence professionals investigating Russia’s interference in the 2016 election.

It began more than a year ago with the president himself attacking the integrity of career law enforcement professionals and repeating the false and baseless claim that the FBI wiretapped Trump Tower. It continued, of course, with the president’s sudden firing of FBI Director James Comey. The president himself acknowledged that the Russia investigation was among his motivations.

More recently, the president’s allies have attempted to exploit the private political opinions of an FBI agent last year as evidence of Democratic bias in the investigation, conveniently ignoring that Mueller removed the agent in question from the investigation upon learning of his comments.

When that argument failed to stick, the president’s allies in the House touted a memo alleging abuses of power during the counterintelligence investigation into the Trump campaign, and refused to back off even after it was apparent that the memo had weaved cherry-picked facts into a deliberately false narrative.

From former FBI director Comey to former deputy director Andrew McCabe, the president has demonstrated a willingness to attack any career law enforcement official who he believes may pose a threat to him.

These efforts to discredit and dismantle a federal investigation dealing with the president’s campaign echo dark times in our nation’s history. Taken as a whole, this campaign of innuendo and misinformation should alarm us all, Republican and Democrat alike.

Amplified by retweets and cable news punditry, these flimsy attacks nevertheless undermine public trust in law enforcement and, consequently, the rule of law. The apparent willingness of the president and his allies to accept this outcome — despite its enormous costs to our democracy — is deeply disturbing.

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Mr. Mueller is a Vietnam War veteran and a lifelong Republican, with impeccable credentials as a man of the law. He has assembled a team that includes some of the nation’s best investigators and prosecutors, and he has led this investigation with the professionalism that a task of this importance requires.

The truth is that Russia attacked us right here at home — not with guns or missiles but through cyber raids and a broad disinformation campaign aimed at undermining our democratic process. Ignoring and politicizing this ongoing threat to our national security will not make it go away.

That’s why we must draw a red line.

Passing legislation to protect the Mueller probe is a necessary start, but our nation’s elected officials must also summon the courage to challenge those in our ranks who would put partisan politics over truth, or who would put the president’s interests over the interests of justice.

Congress must make clear to the president that firing the special counsel, or interfering with his investigation by issuing pardons of essential witnesses, is unacceptable and would have immediate and significant consequences.

In the United States of America, no one is above the law. Not even the president.

Sen. Mark Warner, D-Va., is vice chairman of the Senate Select Committee on Intelligence. Follow him on Twitter: @MarkWarner