Democratic presidential candidate Bernie Sanders celebrates his New Hampshire primary victory at a rally in Concord, N.H., on Feb. 9, 2016. (Jewel Samad/AFP/Getty Images)

With Hillary Clinton’s once-overwhelming lead in Virginia shrinking, it seems that every prominent Democrat in the commonwealth has been deployed to boost her quest for the White House.

Gov. Terry McAuliffe, a close friend who chaired Clinton’s 2008 presidential campaign, was on hand Friday night to open a Clinton campaign office in Richmond. Sen. Timothy M. Kaine made the rounds over the weekend to say Clinton stands “head and shoulders above” Bernie Sanders, his Senate colleague and Clinton’s Democratic primary rival. On Tuesday, Sen. Mark R. Warner went to George Mason University to talk up Clinton’s college-affordability plan.

But the 20 students who braved a cold rain to attend that event said momentum among their generation seems to be shifting to Sanders.

“People look at it as the cool thing to do,” said Travis Evans, 19, a Clinton supporter.

Hillary Clinton supporters come and go at the opening-night rally at the Clinton campaign’s Virginia field office in a strip mall in Alexandria on Feb. 10. (J. Lawler Duggan for The Washington Post)

A loss or even a narrow victory in the commonwealth on March 1 would be deeply embarrassing for both McAuliffe and Clinton, who on Wednesday launched a six-figure television ad campaign in the Richmond area.

As one of the biggest Super Tuesday contests, Virginia — with a Democratic base that includes a substantial number of African American voters — is considered crucial to Clinton’s nomination hopes. McAuliffe, who built a formidable grass-roots operation in Virginia when he won his post in 2013, has long claimed he can deliver the state for Clinton.

“We have a great operation on the ground. We’ve been working it hard,” McAuliffe said this week. “We’re just going to have to gut it out, but I feel very good about where we are here in Virginia.”

A Christopher Newport University poll released Tuesday found that among likely Democratic voters in the state, Sanders was 12 percentage points behind Clinton after trailing by 17 points in October and barely registering last April. A recent Roanoke College poll found that Sanders rated more favorably than Clinton with all registered voters and performed better in individual matchups against Republicans.

“People like him; they trust him,” said Mark J. Rozell, acting dean of the School of Public Policy at George Mason University. “I would not be surprised to see Bernie Sanders do well.”

Sanders opened his first Virginia office in Fairfax in late January, two weeks before Clinton. There were no high-profile guests, just dozens of volunteers.

“He just supports more of what I would want to see when I’m my mother’s age,” said Ewen Crunkhorn, who will turn 18 in time to vote in the primary. “A lot of what he had on his website made a lot more sense.”

Volunteers Maggie Godbold of Herndon, left, and Linda-Lee Slesinger of Oakton, center, along with campaign staffer Ben Harris of Reston, work the phones contacting potential Virginia voters. (J. Lawler Duggan/For The Washington Post)

Sanders has appeared in Virginia three times since launching his campaign, attending an Arlington policy forum in July and events at Lynchburg’s Liberty University in September and at George Mason in October. He also held a rally in Manassas. An army of 7,000 Sanders volunteers is staffing phone banks, making 18,000 to 24,000 phone calls a night to potential Virginia voters. His campaign’s on-the-ground canvassing in the state started at the end of January.

“The energy and the enthusiasm that I’m seeing with these volunteers and supporters, it’s unlike anything I’ve seen in the decade I’ve been working in politics,” said Sanders’s Virginia state director, Peter Clerkin.

Clinton’s campaign has held 450 organizing events across Virginia and is running phone banks seven days a week. Like Sanders, she began sending volunteers to voters’ homes last month. She has the support of the country’s largest union for federal employees — an important endorsement in Virginia, where more people work for Uncle Sam than in almost any other state. But Sanders has been making inroads with the union rank-and-file in Nevada and elsewhere, and it remains to be seen how much weight the endorsement of Clinton by the American Federation of Government Employees will carry with federal workers.

At Warner’s event at George Mason, Lora Popal, a 24-year-old senior, said she wanted to know more about Clinton’s ideas for criminal justice reform. Her brother, she said, was convicted on drug-possession charges and now cannot get a job or a loan.

“When you’re online, on Tumblr, it’s all about [Sanders],” Popal said. College affordability, she added, is not the reason. “It’s because of legalizing marijuana,” she said, whispering the last word. “That’s all they care about.”

Terence Stovall, a 20-year-old sophomore, said that when he wears his “Hillary Clinton 2016” sweatshirt on campus, “you definitely get those looks. It’s the new thing not to be establishment.”

Clinton, however, is sticking with the establishment to rouse her own grass roots. Along with McAuliffe, Kaine and Warner, those hitting the trail on her behalf include U.S. Reps. Don Beyer, Gerald E. Connolly and Robert C. “Bobby” Scott.

“We’re here to make the case to millennials,” Warner said Tuesday. “One of the reasons why I support her is . . . you lay out aspirational goals, but you have to be pragmatic about how to get things done,” Warner said.

A week earlier in Fairfax County, at the opening of Clinton’s first Virginia office, Kaine told an enthusiastic crowd of 200 that the former secretary of state was “head and shoulders” above Sanders. “We love Bernie,” Kaine said. “But why have every last U.S. senator who has endorsed, who knows both of these guys, endorsed Hillary and not Bernie?”

He said that senators such as he could not be dismissed by Sanders as “the establishment,” adding: “I practiced civil rights for 17 years in the South.”

Clinton is thought to have a demographic edge in Virginia over Sanders, who in polls is faring much better with white voters than among blacks and Latinos. She has held conference calls with black ministers in the state, and her allies are appearing at churches and on radio shows in African American communities. The state is 20 percent African American and 9 percent Hispanic.

When McAuliffe opened Clinton’s Richmond office, he was joined by Scott and Secretary of the Commonwealth Levar Stoney, both of whom are African American.

“Secretary Clinton knows 1.5 million African American men are missing from our communities,” Stoney told the crowd of about 120. “That is why she’s been a champion for criminal justice reform for over 40 years. That is why she has stood behind President Obama for his whole, entire term. That is why we need her in the White House.”

McAuliffe highlighted Sanders’s criticism of Obama, echoing a Clinton strategy that analysts say is intended to sway black voters who are protective of the president’s legacy. Sanders “said the president was weak and a disappointment,” McAuliffe said. “I don’t think our president has been weak or disappointing.”

D’Angelo Morrison, 25, a state Health Department staffer who works with people with AIDS and attended the event, said he supports Clinton because “Hillary has the most experience.” Morrison, who is African American, said many of his friends prefer Sanders “because he promised them free things.”

Sanders’s campaign has made an effort to hire a diverse team in Virginia. His field director, Rose Espinola, last worked on Latino outreach for Planned Parenthood. At the Fairfax office opening, she said that the biggest obstacle for Sanders is convincing his supporters that he can actually capture the nomination — and the presidency.

In the same patch of Fairfax on the same night, a far more experienced political hand was making phone calls on Clinton’s behalf. Kris Balderston has worked for Bill or Hillary Clinton for 21 years, most recently leading the State Department’s Global Partnership Initiative.

After 66 calls, he was “heartened” by the enthusiasm he often found on the other end of the line, he said. “I’m going to send her an email and tell her that tonight.”

Karen Tumulty and Laura Vozzella contributed to this report.