By any measure, the scandals enveloping Virginia’s three top Democratic leaders — a toxic stew of racially offensive imagery and an allegation of sexual assault — are potent enough to potentially end any politician’s career.

Yet Gov. Ralph Northam, Lt. Gov. Justin Fairfax and Attorney General Mark R. Herring have managed over the past week to exacerbate their crises in ways that have astonished political professionals.

The nadir may have occurred when the governor, prompted by a reporter’s question, appeared willing to perform a rendition of Michael Jackson’s moonwalk at a nationally televised news conference during which he acknowledged putting on blackface to compete in a 1984 dance contest.

But the cataclysm also has been punctuated and propelled by contradictory statements, untimely barbs and assertions that have seemed insensitive and hypocritical.

Residents in Richmond shared their thoughts on Virginia Gov. Ralph Northam (D) days after a racist photo in his medical school yearbook page surfaced. (Amber Ferguson, Dalton Bennett, Lee Powell/The Washington Post)

For Fairfax, the worst moments may have been Tuesday, when he challenged the credibility of a woman who had accused him of a 2004 sexual assault and insinuated that Northam and Richmond Mayor Levar Stoney (D) may have leaked the allegation.

Herring’s misstep was to demand Northam’s resignation Saturday, only to acknowledge four days later, after his name was floated as a possible successor to the governor, that he himself wore blackface when he dressed as rapper Kurtis Blow while in college.

“Any one of these could be a case study for future analyses of how not to handle a political crisis,” said Mark Rozell, a George Mason University professor of public policy. “In each case, their public comments have amplified the situation rather than tamped it down.”

The trio’s handling of their respective imbroglios has triggered rounds of backbiting, second-guessing and outright mocking from Richmond to the U.S. Capitol to late-night television, where Stephen Colbert said of the governor, “You might want to learn to moonwalk away right now.”

“The mistake is everyone panicked,” said a former elected official from Virginia who asked not to be identified because of the sensitivity of the matter. “The best thing is, take a deep breath and wait until the facts come in. That’s the lesson here. Otherwise your message is confused. It’s Politics 101, and each one failed.”

Rep. A. Donald McEachin (D-Va.) said Northam’s management of the crisis — saying he was in a photograph showing a person in blackface and a person in a KKK hood, only to deny he was in the picture 24 hours later — suggests “that he does not have the capacity to lead or heal us.”

"Between going back and forth — it's me one day, it's not me the next day — all those things poorly handled the situation," the congressman said Thursday.

McEachin also criticized Fairfax, saying he dealt with his crisis “poorly,” though he called any demand that the lieutenant governor resign “premature.”

“One of the curses of being an African American man in the United States is that you don’t get to play the angry man,” the congressman said. “He should have been much more deferential to the woman in question. There should not be heated conversations with our mayor. As much you may be angry on the inside, it doesn’t help things to portray that on the outside.”

Lanny Davis, who was President Bill Clinton’s White House counsel and specializes in crisis management, said that the trio violated his first maxim, which is to tell the truth “early and tell it before anyone knows about it.”

“The key word is ‘authentic,’ ” said Davis, whose clients include Michael Cohen, President Trump’s former attorney. “What makes it authentic is contrary to your political interest. You must convey sincerity by not looking like you’re opportunistic in your apology.”

In Northam’s case, Davis said, his first mistake was that he failed to acknowledge as far back as the gubernatorial campaign that the racially offensive photo had appeared on his medical-school yearbook page.

“If he didn’t know about the yearbook, he should have known,” Davis said. “He should have held a press conference and put it to the electorate. He should have apologized profusely and at the same time said there’s no way to apologize, there’s no way to say, ‘I’m sorry.’ This is something he still hasn’t done.”

“Never ever say one word or syllable after ‘I’m sorry,’ ” Davis said. “There’s not ‘I’m sorry, but it wasn’t me in the photo.’ Never say, ‘I’m sorry, but the sex was consensual.’ Never say, ‘I’m sorry, but I was imitating a rapper.’ It doesn’t work.”

The history of American politics is littered with examples of politicians who have fumbled their way through searing scandals, a litany that includes Clinton, who managed to remain in office despite his affair with White House intern Monica Lewinsky.

In some instances, politicians have been known to take responsibility for their actions, such as President Grover Cleveland, who acknowledged that he had fathered a boy out of wedlock and financially supported him.

A century later, President Ronald Reagan went on television to claim responsibility for trading arms for hostages after denying only months before that his administration had done so. “My heart and my best intentions still tell me that is true, but the facts and evidence tell me it is not,” Reagan told the country.

It was the kind of truth-telling moment that might have helped President Richard M. Nixon during Watergate, Rozell said. “So often, it’s not the scandal that brings them down,” he said. “It’s how they responded to it.”

Before the past week, Northam, Fairfax and Herring, along with Virginia’s Democratic Party, were riding high, poised to dive into another gathering of the General Assembly and then help candidates in legislative races across the state.

But the publication last Friday of Northam’s yearbook photo by a conservative website drew a gaggle of network news cameras to Richmond and soon set off a cascade of revelations, including Vanessa Tyson’s charges against Fairfax and Herring’s admission about his own episode with blackface.

“The three scandals reinforced each other and made it a national story,” said Larry Sabato, a political science professor at the University of Virginia and director of its Center for Politics. “Everyone, including them, was taken by surprise. All of a sudden, it wasn’t clear if they could hang on. And even if they do hang on, they’re weakened.”

Sabato said that Northam failed to grasp the gravity of his situation and that his reversal in the first 24 hours guaranteed him “hours of time with the late-night comics.”

“He became a joke and a pariah,” Sabato said. “. . . He didn’t recognize that this was a career-threatening moment. You’re halfway to losing your post when you don’t recognize a mortal threat.”

On Wednesday, Northam hired IR+Media, a Washington-based crisis management firm.

“They may or may not be able to hang on,” Sabato said of the Democratic leaders. “But I would be surprised if this doesn’t permanently affect how people see them.”