The political crisis in Virginia spun out of control after the state's attorney general confessed to putting on blackface in the 1980s and a woman went public with detailed allegations of sexual assault against the lieutenant governor.
Mr Northam has come under pressure from almost the entire state and national Democratic establishment to resign after the discovery of a photo on his profile page in the Eastern Virginia Medical School yearbook of someone in blackface standing next to a person in a Ku Klux Klan hood and robe. At a surreal news conference the next day, he reversed course and said he was convinced he wasn't in the picture. Northam initially said he was in the photo, then denied it, but acknowledged putting shoe polish on his face for a dance contest in Texas in 1984, when he was in the army.
Herring, who like Northam is white, is second in line to succeed the governor as attorney general.
Fairfax had always been considered a rising star in the party who drew praise for taking a stand against a ceremony honoring Confederate Gen. Robert E. Lee just last month.
Tyson wrote in her statement that "what began as consensual kissing quickly turned into a sexual assault".
Ms Tyson, a 42-year-old political scientist who is on a fellowship at Stanford University, said she was not motivated by politics to come forward, writing: "I am a proud Democrat".
Tyson first brought the accusation to The Washington Post in November 2017 and January 2018, although The Post declined to publish it because they could not corroborate her claims. First and foremost among the questions they raise: How could he possibly have admitted to something as damning as appearing in the photo if he was certain he wasn't one of the people in it?
And visibly pained state lawmakers dodged cameras and reporters as they tried - with difficulty - to keep their focus on legislation during what is considered the busiest time of year for the deliberative body. At one point, NBC reported, he said, "F**k that bitch".
He admitted at first that he was in the photo without saying which costume he was wearing.
Northam has continued to cling to power, hunkered down in the governor's mansion in Richmond, despite facing calls to resign from nearly the entire Democratic party in Virginia, and a number of prominent black public figures.
Kirk Cox, 61, the Republican speaker of the Virginia House of Delegates, is third in the state's constitutional line of succession.
Republican Del. David Yancey was tied with Democrat Shelly Simonds after all votes were counted in the 2017 Virginia election.
"I am not surprised that those wanting to engulf Republican leaders in the current situations involving the Governor, Lieutenant-Governor, and Attorney-General would highlight the yearbook from my graduation a half century ago", said Norment, 72.
Some Northam supporters are scrambling to show that the governor still has backing among members of his party.
Georgia Democrat Stacey Abrams wouldn't call on the embattled trio of Virginia Democrats to resign in an interview Thursday, saying they should take "responsibility for their decisions".
Ertel apologised in a Facebook post on Sunday, according to media reports. "Over the past several days, he has even toyed with the idea of leaving the Democratic Party and governing as an independent - a sign of the degree that he is isolated from every political ally, from his state party and from the national party".