President Trump campaigns for Republicans in Estero, Fla., on Wednesday night. (Joe Raedle/Getty Images)

President Trump is fond of asserting that “Collusion is not a crime, but that [it] doesn’t matter because there was No Collusion.” Signs are gathering that both of those claims may be challenged by special counsel Robert S. Mueller III. As longtime criminal law practitioners, we believe that the first indictment of someone within Trump’s inner circle could be imminent for collusion-related crimes of the kind we detail in a new report. If such charges are filed, that would have profound consequences for those around Trump, the president himself and for our democracy.

That target appears to be Roger Stone, the political provocateur and longtime Trump confidante. Stone himself has said he believes he may be indicted, declaring that “Robert S. Mueller III is coming for me” and raising legal defense funds. In our view, he has ample reason for concern. Mueller has already issued two indictments laying out the Russian attack on our democracy, and one of those indictments seems to point to Stone as “a person who was in regular contact with senior members of the presidential campaign of Donald J. Trump” who had discussions with a Russian operative using the handle “Guccifer 2.0.” Stone has acknowledged that he is likely the person named in the indictment. And just last week Mueller reportedly interviewed former Trump campaign chief strategist Stephen K. Bannon about Stone’s private statements regarding WikiLeaks and the emails it later released.

Stone forcefully denies any wrongdoing. In response to questions from The Washington Post, he said that “if the decision is based on evidence, facts and truth, no charges will be brought against me.”

But Mueller may not agree. Portents that an indictment could issue soon also include the recent grand jury appearances of Stone associates. There reportedly has been testimony by Randy Credico, who may have been a conduit between Stone and WikiLeaks founder Julian Assange, and Jerome Corsi, who may have been called to testify about information he shared with Stone. Others around Stone were issued grand jury subpoenas to appear as well, including one who refused to comply and has been held in contempt.

In our near-century of combined criminal law experience, all these indicators point to potential charges. Indeed, but for the Justice Department’s practice of avoiding indictments that could affect an election in the 60-day window before balloting, the Stone indictment might have been issued already. When that blackout period ends, Mueller may be ready to move.

That is when things will get interesting. With each indictment, the special counsel is inching closer and closer to the president. Stone spoke regularly to Trump for years, worked for Trump on the campaign for a time and continued to communicate with him thereafter, including when Trump ascended to the White House. It will be much harder for Trump to continue his two-pronged collusion denials if someone as close to him as Stone is indicted.

The risk to the president would deepen if Stone chose to cooperate. Stone is defiant now. But so was Trump’s former campaign chairman Paul Manafort. Manafort was willing to see the fight through to conviction on eight separate counts before he finally acceded to the possibility that even with a potential pardon, he might be better off playing ball with the special counsel’s office. He has reportedly met with them nine times in the past four weeks to proffer what he knows.

That is not just a precedent. It is also a pressure point: Manafort is a longtime Stone associate as well. He surely has been questioned about his knowledge of any Russia-related communications by or with Stone, including ones involving candidate Trump or those around him.

If Stone were to cooperate, he could have much to say. We know that Trump campaign officials had at least 87 reported contacts with Russia-linked individuals and officials during the 2016 election cycle. Among those was the infamous Trump Tower meeting between Russian nationals and senior members of the campaign in June 2016, for which Donald Trump Jr. was promised “information that would incriminate” Hillary Clinton, and to which he responded, “If it’s what you say I love it especially later in the summer.” That was, of course, when the stolen Democratic National Committee email was released — and Mueller, it seems, has already alleged that Stone had contacts with a Russian entity involved (though Stone says those contacts all came after the initial release of the emails).

After next week’s election, Mueller could also ratchet up the pressure on Trump by producing his report on collusion or obstruction of justice. On the former, the special counsel has reportedly turned his focus to Trump, submitting questions to him to answer in writing. On the latter, there is already substantial evidence of presidential obstruction. Speculation has been intense that an obstruction report could also drop after the 60-day election blackout ends.

The president is not one to passively await these legal walls closing in on him. He has wild cards of his own to play: Media reports and congressional observers alike suggest that after the midterm elections, Trump will clean house at Justice. He could fire Mueller’s supervisor, Deputy Attorney General Rod J. Rosenstein, replacing him with a crony who will choke off the investigation. A new supervisor could potentially even go so far as to bar the special counsel from filing indictments or block him from disclosing his findings to Congress or the public.

Or Trump could leave Rosenstein in place but seek to take away his supervisory authority by firing Attorney General Jeff Sessions. The deputy attorney general oversees Mueller only because the attorney general had a conflict owing to his ties to Trump. Any new attorney general should also recuse, given the president’s many statements that he expects his attorney general to protect him. But whomever the president chooses might not take that ethically necessary step. If the attorney general is replaced by a Trump crony, he or she might seek to assume oversight of Mueller, or even claim the special counsel is no longer needed — an outcome the president, too, could try to order. Like Richard Nixon’s Saturday Night Massacre, those outcomes would threaten a constitutional crisis, with the president taking steps to put himself above the rule of law.

Of course, we do not know whether Mueller’s implacable forward motion in the direction of the president will lead to a collision with the president’s open hostility to the investigation. Trump may back down from stimulating a crisis, as he has done before. But if the weeks after the election bring a Stone indictment and perhaps one or more Mueller reports, tensions could well intensify, if not erupt into outright conflict.

Ultimately, though, the real power doesn’t belong only to Mueller or Trump. It also resides with members of Congress, and the voters who put them there. The majority leadership in Congress has failed to hold Trump accountable. The House has particularly abdicated its oversight role. If it remains led by those in his own party who have repeatedly turned a blind eye to Trump and his administration, he may take that as license to do as he pleases. Conversely, if the election results in at least one body of Congress in a position to exercise real oversight, that may check the president’s willingness to provoke a constitutional clash. He will know that if he disrupts the investigation, there is an authority beyond his control that can take it over.

With voting less than a week away — and already well in progress in many states — the outcome of the looming clash appears to reside exactly where it belongs in a democracy: with the American people.