The United States may not quite be in a constitutional crisis, but it certainly feels like one. With Michael Cohen’s guilty plea this week, and his admission in court that he paid illegal hush money to two women at then-candidate Donald Trump’s behest, the president is effectively an unindicted co-conspirator in a plot to break campaign-finance laws to influence his own election. What’s more, it’s not even the plot he’s denied taking part in for more than a year.

The guilty plea by Trump’s former personal lawyer sends this presidency, and the nation, even further into uncharted waters. There’s now a deep unease across the American political spectrum, a sensation akin to the swelling hum of instruments as an orchestra warms up for its performance. Politico reported that Tuesday’s legal maelstrom “left an unavoidable impression that the walls are closing in on a president facing serious accusations of wrongdoing” among White House staffers. Elsewhere in Washington, Trump’s opponents appear to sense the advantage turning in their favor.

“Enough is enough,” New York Representative Jerrold Nadler said in a statement on Wednesday. “The President of the United States is now directly implicated in a criminal conspiracy, numerous members of both his campaign and administration have been convicted, pleaded guilty to felonies, or are ensnared in corruption investigations, and the Judiciary Committee has real work to do.” If Democrats retake the House this fall, Nadler would preside over impeachment hearings as chairman of that committee.

There is no clear path to how all of this ends. Trump’s political wounds are so grievous, and his unpopularity so thoroughly baked in for the American public broadly (just as, conversely, his popularity with Republicans is), that it’s hard to imagine how he could ever have anything resembling a normal presidency. At the same time, it’s unclear if his opponents could successfully oust him through impeachment. Many of these questions depend on the fate of the 2018 midterms, and perhaps all depend on whatever legal twists and turns come next.

Trump’s chief advantage at the moment is that he is the president. Without that office, he would be as susceptible to an indictment for criminal wrongdoing as any other American. There’s a robust debate among legal scholars on whether a president can be indicted while in office, but the question is effectively moot since it would violate current Justice Department guidelines. It’s a grim paradox that the man commanded by the Constitution to “faithfully execute” the laws of the United States is also the person who is least beholden to them.

This problem is not completely new, of course. Two presidents have been formally implicated in criminal behavior in Trump’s lifetime. The archetypal case is the Watergate crisis, when Richard Nixon tried to cover up a break-in of Democratic headquarters by his associates. More recently, the House of Representatives impeached Bill Clinton for lying to a federal grand jury about his relationship with a White House intern. (He was subsequently acquitted by the Senate.)

At some point, Trump will no longer be the president. Should he be indicted then? No president has ever faced criminal prosecution after leaving office, though it has been contemplated. Nixon’s resignation immediately raised the question of whether he would face criminal charges. Leon Jaworski, the Watergate special prosecutor, did not reach a definitive conclusion on whether to proceed because he was waiting for the trial of John Mitchell, Nixon’s former attorney general, to wrap up first.

“A decision on whether or not to indict was not a pressing matter at the moment because, had the decision been to indict, action would not have been taken until after the jury had been selected and sequestered in the Mitchell, et al. cover-up case, then set for the last day of September, because otherwise any indictment of Nixon would have meant an indefinite delay in that trial,” he later recalled in a Fordham University lecture. While the matter was being studied, President Ford moved to pardon former President Nixon.”

Ken Starr, the independent counsel who investigated Clinton for most of the 1990s, left that position in September 1998. His successor, Robert Ray, opted against prosecuting Clinton after the president’s acquittal by the Senate. Instead, he struck a plea bargain of sorts with the outgoing president on his last day in office. Clinton agreed to a five-year suspension of his law license and admitted to “testifying falsely” about his sexual relationship with Monica Lewinsky. In his final report on the matter in 2002, Ray said he believed he could have successfully prosecuted the ex-president for lying to the federal grand jury four years earlier.

That leaves impeachment as the likeliest check on Trump’s power. Congress is supposed to keep the president accountable under the tripartite system of American government, at least in theory. But it has largely abandoned that duty under Republican rule. A substantial clique of House Republicans have spent the last year using their oversight powers to actively undermine the Justice Department’s investigations of Trump. House Speaker Paul Ryan has allowed California Representative Devin Nunes and the clique’s other leaders to keep their committee chairmanships despite the damage they are doing to Congress’s institutional credibility.

If Democrats retake the House in November, impeachment proceedings are far more likely than they are now. But the party doesn’t appear to be convinced that it’s a politically winning issue so far. Democratic leaders in Congress studiously avoid discussing it, as do most (but not all) of the rank-and-file members. Tom Steyer, a billionaire Democratic donor who’s spent millions of dollars promoting impeachment since Trump took office, has reportedly expressed anger toward the party’s leaders for downplaying the issue.

Unforeseen events could change the Democrats’ calculus. If Mueller finds and reveals evidence of serious wrongdoing on the president’s part, it could push Democrats and even some Republicans towards removing him from office. Firing Mueller or shutting down his investigation would likely prompt a similar level of blowback in Congress. But events could also shift in Trump’s favor. Democrats are likely to but not guaranteed to retake the House in this November’s midterm elections; they are much less likely to win the other chamber of Congress, which holds the power to convict or exonerate an impeached president. If Republicans manage to hold on to the House and expand their majority in the Senate, even proof of outright collusion might not be enough to oust him.

After Cohen’s guilty plea, the risk of an explosive counterattack from the president is also even higher. “When Trump is cornered, he is at his most dangerous, as several people close to him have said,” New York Times reporter Maggie Haberman wrote on Twitter on Wednesday. She noted that Trump behaved as though he “had nothing to lose” when the Access Hollywood tape came out during the 2016 election. “This is a different order of magnitude, touching on his business and potentially family,” Haberman wrote.

Trump has already shown a willingness to take extraordinary steps as president in his own self-interest. After his failed attempt to secure FBI Director James Comey’s personal loyalty failed last spring, the president unceremoniously ousted him midway through his ten-year term and then publicly threatened him to keep quiet. Trump also reportedly tried to fire special counsel Robert Mueller last December, only to back down when White House Counsel Don McGahn refused to carry out the order. In recent months, he has increasingly used his Twitter presence to hound and denigrate FBI employees who could be potential witnesses against him.

If tweets aren’t enough, Trump could resort to even more aggressive measures. Jack Goldsmith, who ran the Justice Department’s Office of Legal Counsel under George W. Bush, warned of three possible steps that Trump could take to curtail the Russia investigation after Cohen’s plea deal. First, he could pardon key participants like newly convicted felon Paul Manafort, freeing them from pressure to cooperate with Mueller’s inquiry. Second, he could trigger another Saturday Night Massacre by ordering Justice Department officials to fire Mueller, which many of them would likely refuse to do. Finally, he could weaponize his control over the security-clearance process and yank them from Mueller’s team, as he already did to former CIA Director John Brennan earlier this month.

Any of those moves would likely push many Democrats, who are already planning for such scenarios, and even some Republicans toward removing the president from office. But nothing is guaranteed, and all of the structural advantages are in Trump’s favor. It would take extraordinary acts or revelations for Trump to become the first president to be indicted or impeached. But these also happen to be extraordinary times.