WASHINGTON — It would start within minutes of special counsel Robert Mueller being fired — a torrent of activity ricocheting through the halls of Congress and over television airwaves, including nearly a thousand protests being prepped from the Virgin Islands to Alaska.

Democrats have drafted a wide-ranging contingency plan should Mueller be fired or President Donald Trump take other steps to quash the Russia investigation, like firing Deputy Attorney General Rod Rosenstein or pardoning key witnesses.

Of top concern in the first 24 hours of such a move would be preventing Mueller’s documents from being destroyed and his team disbanded, according to interviews with nearly a dozen lawmakers, congressional aides, Democratic operatives and attorneys involved in the planning.

Almost immediately, Senate Minority Leader Chuck Schumer would consult with Senate Majority Leader Mitch McConnell, while Democrats would demand a floor vote on a bill retroactively protecting Mueller and protecting his materials. In both the Senate and House, rank-and-file Democrats would contact a list of sympathetic Republicans who have signaled privately that they’d be willing to act should Trump pull the trigger.

"We’ve had a lot of conversations about how exactly and who and when and where," Sen. Chris Coons, a Delaware Democrat who sits on the Judiciary Committee, told NBC News. "There have been several moments when it seemed imminent."

And in cities across the country, rallies would be hastily scheduled for 5 p.m., if Mueller is fired before 2 p.m. on any given day. If he’s fired in the late afternoon or evening, the protests would be set for noon the following day.

The Democratic group MoveOn.org has been organizing 933 such rallies, with locations picked out and sponsors enlisted to handle logistics. The list includes rallies in big cities like Los Angeles, along with protests in more remote areas, such as the federal buildings in Bismarck, North Dakota, and Hilo, Hawaii.

It’s unclear how many people would actually turn out, but more than 350,000 people have RSVP'd online to attend. The campaign director for MoveOn, David Sievers, said the group expects that the number of protests will grow and that far more would sign up to attend once news broke of Trump’s actions.

Any success in protecting Mueller would depend heavily on a sudden change of heart by Republicans and their leaders, who have largely defended Trump and thus far refused to allow a full Senate vote on legislation to protect the investigation.

Still, Democrats are hoping that a Mueller firing would be considered so egregious that even Trump's fellow Republicans would be pushed past a tipping point.

Coons predicted that "within minutes" of a Mueller firing, dozens of Republicans would either voice opposition publicly or phone the president or his chief of staff to register their objection privately. But he acknowledged that many Republicans have been coy, refusing to say even behind closed doors what actions they’d be willing to take.

Documents have already been drawn up for a number of contingencies, including a "Saturday Night Massacre" scenario in which Trump systematically fires top Justice Department officials who refuse to fire Mueller until one of them agrees to do so.

The concern has taken on a fresh urgency in recent days as the investigation has tightened around Trump.

On Tuesday, former Trump personal attorney Michael Cohen pleaded guilty to eight counts, including two involving hush-money payments to women that Cohen said were made “at the direction of a candidate,” referring to Trump. In a breathtaking string of events, within minutes Trump’s former campaign chair Paul Manafort was found guilty in another federal court on eight counts of tax evasion and bank fraud, creating fresh concerns for the president that Manafort might cooperate with the special counsel’s investigation.

Warned Schumer, hours later: “He better not talk about pardons for Michael Cohen and Paul Manafort, tonight or any time in the future."

Trump, appearing late Tuesday at a rally in West Virginia, didn’t mention potential pardons. Yet in an interview on Monday, the president had told Reuters that he’s “totally allowed to be involved” in the investigation.

“I could run it if I want," Trump said.

Democrats have also revisited their contingency plans in recent days amid signs the president feels emboldened both to punish those involved in the investigation and to influence it directly.

Last week, after revoking former CIA Director John Brennan’s security clearance and threatening to do the same to other current and former intelligence officials, Trump said that he felt it "had to be done" because "these people led" the Russia probe.

It was the latest sign that even the most senior Republican leaders can neither restrain the president nor predict what lines he will or won’t cross. After all, House Speaker Paul Ryan had dismissed Trump’s earlier threat to terminate Brennan’s security clearance as mere "trolling," as Rep. Adam Schiff, the House Intelligence Committee’s top Democrat, pointed out this week on Twitter.

When @POTUS first threatened to pull John Brennan’s security clearance in July, @SpeakerRyan said he was just “trolling.” If he attempts to remove Special Counsel Mueller, Congressional Republicans cannot claim they didn’t see it coming.



When will the GOP put country over party? https://t.co/8DaMiMI3tP — Adam Schiff (@RepAdamSchiff) August 20, 2018

Other senior figures in the investigation have been fired or forced out since Trump took office, including former Acting Attorney General Sally Yates, former FBI Director Jim Comey and former Deputy FBI Director Andrew McCabe.

After a Mueller or Rosenstein firing, Democrats would take to the floors of the Senate and House to call for obstruction of justice hearings and a special congressional committee to pick up the investigation, similar to the Senate Watergate Committee.

Democratic political groups would demand that the Senate be shut down until there’s a resolution, denying all requests for unanimous consent. Some would call for impeachment proceedings against the president, while others would stop just short, officials involved in the planning said.

To speed up the response, congressional aides said language has been drafted for letters that House Democratic leaders would send to committee chairmen demanding hearings; to inspectors general demanding investigations; and to White House Counsel Don McGahn and the Justice Department demanding information about their communications before the firing.

Mueller himself might be called to testify quickly before Congress. There have been early discussions about whether, if the investigation were shut down and Democrats win a majority in the House in November, they could subpoena testimony already given to the grand jury in the Russia investigation. At a minimum, newly empowered Democrats would call up those who have previously testified and demand they tell Congress what they told the grand jury.

Planning for such emergency Mueller-firing scenarios began more than a year ago, shortly after Attorney General Jeff Sessions recused himself from the Russia inquiry and then appointed a special counsel. House Minority Leader Nancy Pelosi’s team started working on a playbook with Schumer’s team, along with top Democrats on the Judiciary and Oversight panels in Congress.

Meanwhile, a coalition of mostly liberal advocacy groups banded together to hire the Democratic polling firm Greenberg Quinlan Rosner starting in the summer of 2017 to research how the American people felt about the integrity of the Russia investigation. Jeremy Rosner, a partner at the polling firm, said Americans found Mueller to be credible because he was a lifelong Republican who served in the administrations of both parties.

"People were determined to protect the investigation, let Mueller do his job," Rosner said. Still, the polling right away identified that the issue was fluid and that new events could quickly change the perception, underscoring the need for a concerted messaging strategy to shape public opinion.

A "Friday group" of Democrats involved in key committees continues to meet weekly to discuss the Russia investigation, while another weekly meeting takes place among a coalition of outside advocacy groups such as MoveOn, Public Citizen, Indivisible, Common Cause and People for the American Way. Liberal legal organizations such as the American Constitution Society are also involved in drafting legal strategies that could be deployed if needed, individuals involved in the effort said. The American Constitution Society didn’t respond to requests for comment.

Over the last year, the level of concern that Trump might actually kill the investigation has ebbed and flowed, punctuated by his efforts to discredit Mueller on Twitter, his calls for Sessions to stop the investigation and his insistence — echoed by the White House — that he has the power to fire the special counsel himself. Although some legal experts have questioned that, they do not question that one way or another Trump, through his power to fire the Justice Department officials supervising Mueller, could get rid of the special counsel.

There have been false alarms before.

A scare in April, on Friday the 13th, had Democratic groups and lawmakers on the verge of putting their plan into action. Trump, sensing he was losing control over the investigation, had been going hard after Rosenstein, especially after the special counsel handed off part of the investigation — dealing with former Trump personal attorney Michael Cohen — to a different team of prosecutors in the Manhattan U.S. attorney’s office.

So when Rosenstein headed to the White House for a meeting with Trump, speculation about his imminent dismissal reached fever pitch in Washington.

"The rumors were sounding very specific. They were sounding really imminent," said Elizabeth Beavers of the group Indivisible, part of the coalition organizing the response plan.

Activists across the country who’d agreed to organize rallies started advertising to remind people where to show up if needed. Indivisible hosted an emergency “Facebook Live” video chat to lay out the plan and solicit more phone numbers for potential protesters.

And in Congress, Democrats huddled in their offices long after the sun went down, anticipating the news that never came.

"That was a very late night," said Coons, the Delaware senator.

Different Democrats have laid out different red lines for what actions by Trump would trigger a full-blown crisis response. In December, Sen. Mark Warner of Virginia, the top Democrat on the Senate Intelligence Committee, said Trump would be breaching a red line if he removed Mueller from his job, pardoned key witnesses or shut down the investigation. MoveOn has added replacing Rosenstein or repealing the special counsel regulations to the list, but notes that firing Sessions — who remains recused from the Russia probe — would "be one step short of the break glass moment."

The most likely legislative vehicle for trying to protect Mueller after the fact would be a compromise bill co-sponsored by Coons and Sen. Cory Booker, D-N.J., along with GOP Sens. Lindsey Graham of South Carolina and Thom Tillis of North Carolina. That bill would put in statute that the special counsel could challenge his firing in U.S. District Court, and would require his “personnel, documents and materials” to be preserved in the meantime.

Although the bill already passed the Senate Judiciary Committee with bipartisan support, McConnell has said it won’t get a vote on the Senate floor, arguing there’s no need because the president won’t really fire Mueller.

But the bill specifically states that it’s retroactive — meaning it could be passed after Mueller was fired and still protect him. Democrats are counting on the fact that the public uproar after a special counsel ouster would be enough to change McConnell’s mind and allow a vote.