Northam, who apologized earlier Friday for appearing in a racist yearbook photo showing one person dressed in blackface and another in the Ku Klux Klan's signature white hood and robes, became a politician with few allies after a series of calls from prominent Virginia Democrats loosened the governor's hold on his job.

Statements from the Virginia Legislative Black Caucus, the Virginia House and Senate Democrats and former Virginia Gov. Terry McAuliffe -- who was governor when Northam was lieutenant governor -- ratcheted up the tension on Friday night. In the span of 30 minutes, the three groups and Northam's predecessor all announced -- after a series of conference calls and meetings with the governor -- that they believed the governor must step aside.

The pressure on Northam to step down continued into Saturday ahead of his expected news conference with the Democratic Party of Virginia calling for his immediate resignation.

"We made the decision to let Governor Northam do the correct thing and resign this morning - we have gotten word he will not do so this morning," party chair Susan Swecker said in a statement, adding, "He no longer has our confidence or our support. Governor Northam must end this chapter immediately, step down, and let Lt. Gov. Justin Fairfax heal Virginia's wounds and move us forward."

The Virginia Legislative Black Caucus initially declined to call for Northam's ouster on Friday, saying they were "still processing what we have seen about the Governor" but labeling it "disgusting, reprehensible and offensive."

But in a major moment later Friday evening, the caucus called on Northam to resign in a shift that signaled he was losing some key supporters.

"We just finished meeting with the governor. We fully appreciate all that he has contributed to our Commonwealth. But given what was revealed today, it is clear that he can no longer effectively serve as Governor. It is time for him to resign, so that Virginia can begin the process of healing," the caucus said in a statement.

Northam's meeting with the Virginia Legislative Black Caucus

Del. LaMont Bagby, a member of the Virginia Legislative Black Caucus told CNN Saturday that during their meeting with Northam Friday night, that the governor could not recall when the racist photo was taken that appeared in his medical school yearbook.

When pressed by the caucus, Northam said he did not know which person he was in the photo -- the person in blackface or the person in the KKK outfit.

While he thinks both are offensive, Bagby said he was much more bothered by the KKK outfit.

Bagby told CNN that the governor was apologetic and conciliatory -- that he listened carefully to the concerns of the caucus and did not in any way defend the photo or the actions that led to it.

Bagby said the caucus informed the governor in a face-to-face conversation that they would be calling for his resignation.

The governor told them he would hold a news conference on Saturday -- but did not say if he would resign.

Bagby said he likes Northam and believes he is a good man, but is hopeful that he will do the right thing by the Commonwealth and step down, adding, "I suspect he will."

Virginia Democrats pull their support

The Virginia Legislative Black Caucus' statement Friday was followed by a series of others that marked the moment the floor of support fell out from under Northam.

McAuliffe and Northam had a "long talk" before the former governor's statement went out, according to a source with knowledge of the call.

McAuliffe informed Northam during the call that he was going to call on him to step down, the source said.

Virginia House Democrats, a key block of support for the second-year governor, also pulled away from the governor late Friday.

"We are so deeply saddened by the news that has been revealed today," said the caucus. "We regret to say that we are no longer confident in the Governor's representation of Virginians. Though it brings us no joy to do so, we must call for Governor Northam's resignation."

Virginia Senate Democrats added that they were "shocked, saddened and offended" by the picture.

"The Ralph Northam we know is a pediatric neurologist, a dedicated public servant, and a committed husband and father," the Senate Democrats said. "Nevertheless, it is with heavy hearts that we have respectfully asked them to step down."

On Saturday, Virginia House Republicans joined their Democratic colleagues in calling for Northam's resignation.

"We withheld judgement last night while awaiting an explanation from the Governor believing the gravity of the situation deserved prudence and deliberation," the statement read. "We agree with the powerful words of our colleagues in the Virginia Legislative Black Caucus and believe that because of this photo the Governor has lost the confidence of the citizens he serves."

Virginia congressional delegation reacts, with some not ready to call for Northam's resignation

The series of damning statements came after a number of high-profile Virginia Democrats had indicated that they were not ready to call for Northam's resignation, leaving some Democrats to believe the governor could hang on.

Sens. Tim Kaine and Mark Warner refrained from calling on him to resign. Both said they were shocked and offended by the photos, but in separate statements both said it was time for the governor to think about what comes next for him and to listen to those he has offended.

"The racist photo from Governor Northam's 1984 yearbook is horrible. This causes pain in a state and a country where centuries of racism have already left an open wound," Kaine said in a statement. "I hope the Governor—whose career as an Army officer, pediatrician and public official has always manifested a commitment to justice and equality for all—now takes the time to listen to those he has hurt and reflect on how to move forward."

Warner said Northam must "carefully consider what comes next."

"This photo is shocking and deeply offensive, all the more so because of Virginia's long and painful history of racism and violence toward African Americans. The Governor must now listen to the people and communities he has hurt," he said.

Northam, for his part, has vowed to finish his one and only term as Virginia governor, issuing a video statement on Friday evening where he apologized but pledged to remain in office.

"I cannot change the decisions I made nor can I undo the harm my behavior caused then and today," he said, saying he accepts responsibility for his actions. "I am committed to continuing that fight."

But it became clear to many Virginia Democrats on Friday night that the tide was turning on Northam.

Rep. Elaine Luria, a freshman congresswoman from Virginia, broke with Kaine and Warner and called for him to step down.

"We need leaders who will bring us together instead of driving us apart. While it was proper for Governor Northam to apologize, there is no excuse for this type of photograph then or now," Luria said. "Unfortunately, the existence of this photograph does not bring us together. I ask Governor Northam to resign. This isn't about politics, this is about what is right and wrong."

As did Rep. Abigail Spanberger, another freshman congressional Democrat.

"Such conduct is unacceptable for any Virginian—whether occurring in the past, present, or future," she said. "Governor Northam must resign and fully acknowledge the painful past these images evoke. Bigotry has no place in Virginia."

2020 Democratic candidates call for Northam to step down

Similar calls for resignation came from a number of 2020 presidential candidates, members of Congress and prominent liberal organizations, all of whom said Northam's apology on the issue was not enough. The NAACP also called for Northam to leave office.

The photograph, which was obtained by CNN, appears in the 1984 yearbook for Eastern Virginia Medical School yearbook . Northam apologized in a statement on Friday and did not say if he was wearing the KKK outfit or blackface, but the governor's repentance was far from enough for Democrats like Sen. Kamala Harris, former Housing and Urban Development Secretary Julián Castro and a cadre of powerful Democratic organizations.

Castro was the first Democratic presidential candidate to call for Northam's resignation.

"It doesn't matter if he is a Republican or a Democrat. This behavior was racist and unconscionable," he tweeted. "Governor Northam should resign."

He was quickly joined by others, including Harris.

"Leaders are called to a higher standard, and the stain of racism should have no place in the halls of government," she tweeted. "The Governor of Virginia should step aside so the public can heal and move forward together."

Former Vice President Joe Biden called for the governor to resign, saying "there is no place for racism in America" and "Northam has lost all moral authority."

There is no place for racism in America. Governor Northam has lost all moral authority and should resign immediately, Justin Fairfax is the leader Virginia needs now. — Joe Biden (@JoeBiden) February 2, 2019

Of all the potential Democratic candidates next year, Biden has been the biggest Northam supporter, campaigning for Northam in October 2017 and raising money.

And Sen. Elizabeth Warren of Massachusetts, who launched a presidential exploratory committee in December, joined the others.

"These racist images are deeply disturbing," she said. "Hatred and discrimination have no place in our country and must not be tolerated, especially from our leaders -- Republican or Democrat. Northam must resign."

Sen. Kirsten Gillibrand, of New York, who has announced she's running for president, initially stopped short of calling for Northam to step down, noting she had not seen the photo. Later on Friday night, she said she had seen the photo and felt it was time for Northam to leave.

"There aren't two sets of rules for our friends and our foes: Right is right and wrong is wrong. Americans deserve to be respected by their leaders, and racism cannot be excused in our government or anywhere else. Having seen the photo, I believe Governor Northam should resign," Gillibrand said on Twitter.

Sen. Cory Booker, of New Jersey, on the day he entered the presidential race, tweeted, "These images arouse centuries of anger, anguish, and racist violence and they've eroded all confidence in Gov. Northam's ability to lead. We should expect more from our elected officials. He should resign."

Sen. Bernie Sanders, I-Vermont and Rep. Eric Swalwell, D-California, two others who might seek the 2020 Democratic nomination, joined with those calling for Northam's ouster.

"No, you can't wear a black face or a white hood and lead a state. Not now and not ever," Swalwell tweeted. "But we are merciful people. Governor Northam should step down, seek forgiveness, and through good deeds earn the respect of the African-American Community."

The series of 2020 Democrats urging Northam to resign were also joined by a growing group of powerful Democratic leaders and outside organizations.

"Black face in any manner is always racist and never okay," said Derrick Johnson, President of the NAACP. "No matter the party affiliation, we can not stand for such behavior, which is why the @NAACP is calling for the resignation of Virginia Governor @RalphNortham."

Northam apologizes, does not resign

Northam, a former pediatric neurosurgeon and Army doctor, won the governorship in 2017. In a statement released hours after the photo was first published by the far-right website Big League Politics, Northam confirmed he was in the photo and said in a statement that the costume was "clearly racist and offensive."

In a straight to camera video he later posted, Northam apologized again and said, "I cannot change the decisions I made nor can I undo the harm my behavior caused then and today."

The photo fell "short of the standard you set for me when you elected me to be your governor."

But he did not resign and vowed to serve out the remainder of his term.

If Northam were to heed the calls of those prominent Democrats looking to pressure him into stepping down, Justin Fairfax, the 39-year old, African American lieutenant governor, would be elevated to governor.

A spokesperson for Fairfax said the lieutenant governor spoke with Northam on Friday. The spokesperson did not provide any insight into their call.