CNN  — 

Before he left Washington in disgrace on January 20, 2021, Donald Trump vowed: “We will be back in some form.” On this, at least, he was truthful.

The 45th President never really went away as his baleful influence lingers and his election lies fester with most Republican lawmakers still scared of his personality cult. And on Tuesday, Trump will return for the first time since he slunk out of a city traumatized by his coup attempt and ringed in steel to deter his insurrectionists.

While he’s been exiled from Twitter and has been fuming away in his palace at Mar-a-Lago, Washington has spent almost every day since he left struggling with his legacy.

The eve of a visit that will encapsulate Trump’s still vibrant threat to democracy as he fires up a 2024 campaign was no different. Revelations on Monday that a senior aide to ex-Vice President Mike Pence testified to a federal grand jury offered the first possible glimpse of a Justice Department probe into events surrounding the January 6, 2021, insurrection.

The House select committee investigating the attack released damning new evidence of Trump’s dereliction of duty as his mob ransacked America’s democratic citadel. And President Joe Biden fired off his most disdainful criticism yet of his predecessor over the “medieval hell” that Trump visited on police officers who fought his “Make America Great Again” rioters at the US Capitol.

Only now, after a summer of blockbuster televised hearings from the House select committee, is the full scale of Trump’s political malfeasance becoming clear. And the 45th President is spoiling for more.

He is not returning to Washington on a ceremonial visit as a retired commander-in-chief claiming membership in the exclusive “President’s club.” That’s one fraternity Trump would never want to join. And he wouldn’t be welcome anyway. The 76-year-old former President is instead on the comeback trail. He will address the America First Agenda Summit, a gathering of former aides and officials from his administration who are trying to impose a coherent policy framework on the chaos of Trumpism.

Millions of Americans voted for Trump in 2016 because they rejected what they saw as remote political elites and global trade deals that cost them jobs and saw him as a guarantor of a mainly White, conservative American culture they saw threatened by rapid social change and a fast-diversifying nation. Yet Trump’s presidency, and the manner of his leaving it, poses a question that goes beyond legitimate ideological struggles that have long divided Americans: What are the implications for the nation of a potential presidential candidate who was willing to destroy American democracy to stay in power and to crush the will of a majority of voters who wanted him gone?

Furthermore, Trump legitimized the use of violence to solve political disputes and to try to enforce the will of a minority – an act contrary to the spirit of America’s more-than-two-century-old political experiment. This is why the prospect of a new Trump campaign for the White House comes with such a grave undercurrent.

Trump is still dominating Washington

Ostensibly, Tuesday’s appearance will give Trump the chance to begin fleshing out a policy agenda for the campaign that sources tell CNN he is desperate to launch any day, even if the GOP would prefer him to wait until after the midterms. But if recent experience is any guide, Trump’s speech will be overtaken by his lies and self-obsession about his loss to Biden in 2020.

On the eve of his return, and even as the Biden White House battled to push back on the idea the US is plunging into a recession, Trump was at the center of great events in Washington that may still expose him to legal censure.

It emerged on Monday that Marc Short, Pence’s ex-chief of staff, testified to a federal grand jury investigating what happened on January 6, 2021. Short confirmed to CNN’s Erin Burnett on Monday evening that he spoke under subpoena but said he couldn’t say more, citing legal advice. The New York Times and Wall Street Journal reported Monday that a second top former Pence aide, Greg Jacob, was subpoenaed in the inquiry and testified before the federal grand jury.

The revelation that former senior White House officials went before the grand jury raised the possibility that a wide-ranging Justice Department probe is taking place that had not previously been visible – in what would be a hugely significant development.

On another front, the House select committee released damning new evidence Monday that showed Trump was unwilling to forcibly condemn the rioters a day after their rampage through the Capitol. The then-President, whose handwriting was later identified under oath by his daughter Ivanka, removed references in a speech to the culprits deserving jail and not representing him.

Biden – whose political legacy will rest on confining Trump to a single wrecking ball term in 2020 and may depend on his capacity to defeat him again – once tried to ignore Trump. As he tried to move the country on and bring it together, he referred to his predecessor as “the other guy.”

But on the eve of Trump’s return to Washington, Biden launched one of his most strident attacks yet on his predecessor, prompted by the horrifying evidence amassed by the House committee.

The President was personal, disdainful and direct about Trump.

“We saw what happened: the Capitol Police, the DC Metropolitan Police, other law enforcement agencies were attacked and assaulted before our very eyes. Speared. Sprayed. Stomped on. Brutalized. Lives were lost,” Biden said in virtual remarks to a conference of Black law enforcement officers in Florida.

“And for three hours, the defeated former President of the United States watched it all happen as he sat in the comfort of the private dining room next to the Oval Office,” Biden said, describing police officers at the US Capitol as subject to “medieval hell for three hours, dripping in blood, surrounded by carnage.”

“Face to face with a crazed mob that believed the lies of the defeated President, the police were heroes that day. Donald Trump lacked the courage to act,” Biden said, praising law enforcement officers for saving America’s democracy.

The President’s comments sounded a lot like a preview of a potential campaign against Trump, should the former President go ahead with a candidacy and win the GOP nomination and if the current President makes good on his vow to run for reelection.

Trump faces questions over his popularity

While he remains deeply popular among conservative base voters and polls show he is the hottest prospect in the first rumblings of the Republican 2024 primary, Trump arrives in Washington with questions over his political strength. While many Republican voters have tuned out of the summer of hearings from the House select committee, the revelations about his conduct can hardly have helped his standing among a general election audience given his existing problems with suburban voters.

There are also signs of tentative, yet significant challenges to Trump. Pence, who held a dueling political event with his former boss in Arizona on Friday, was due to speak in Washington on Monday night but his flight was postponed owing to stormy weather. The former vice president intended to make a clear distinction between Trump’s harping on his lies about the last election and the evolution of the conservative movement at the Heritage Foundation.

“Some people may choose to focus on the past. … But I believe conservatives must focus on the future,” Pence planned to say, according to his prepared remarks reported by CNN’s Michael Warren.

The former vice president damaged his standing with Trump’s most loyal voters by refusing to trash his oath to the Constitution, ignoring Trump’s pleas for him to block the certification of Biden’s win – a step he had no power to take. And polls show that Pence is a long-shot for the Republican nomination in 2024 if he runs.

But Trump’s acceleration of the 2024 presidential campaign, which will be at the forefront of his speech on Tuesday, is forcing an early test of where the party wants to go. And other potential candidates, not just Pence, will have to decide whether they have the courage to stand up to the ex-President and buck the trend of Republicans who have always excused or abetted his extremism.

CORRECTION: This story has been updated to reflect that it was Marc Short who confirmed to CNN’s Erin Burnett that he complied with a subpoena.