It has been eight years since any Maryland congressman lost a reelection bid, a statistic underscoring the difficulty challengers face to overcome incumbents’ advantages in campaign cash and name recognition.

With all eight of the state’s U.S. House members on ballots in Tuesday’s primary, their opponents find themselves as underdogs — not only for the usual reasons, but because the new coronavirus has limited their ability to become better known.

Just ask state Sen. Jill Carter, who is part of a crowded field seeking the Democratic nomination for the Baltimore-area congressional seat long held by Rep. Elijah Cummings, who died last October.

Democrat Kweisi Mfume handily won a mostly vote-by-mail special election April 28 over Republican Kimberly Klacik to fill the remainder of Cummings’ term.

Mfume, Carter and other Democratic candidates — including Maya Rockeymoore Cummings, the late congressman’s widow — are now vying for a new term in the 7th Congressional District beginning in January. Klacik, a commentator and nonprofit founder, appears again on the Republican ballot.

The 7th District includes parts of Baltimore City, Baltimore County and Howard County. Tuesday’s primary is also being held largely by mail, with more than 420,000 ballots sent to district voters. They must be postmarked by Tuesday or left in election drop boxes by 8 p.m. that day.

Carter’s state Senate district overlaps the congressional district, meaning many voters already knew her. She picked up endorsements from progressive groups and adopted a catchy slogan, “Jill on the Hill.” But the pandemic and resulting stay-at-home orders derailed opportunities to reach voters.

“I was just going to door-knock every single day,” said Carter, a progressive who emphasizes criminal justice reform and “Medicare for All” health coverage. “The area I represent now, I have a very strong base. The challenge has been getting known outside of that.”

Also, Carter said she was reluctant to ask small donors for funds at a time when the pandemic has cost so many people their jobs.

Other challengers, some running for the first time, are facing similar limitations.

“We know candidates raising the high-dollar donations are always at an advantage, but even more so right now,” said Joanne Antoine, executive director of Common Cause Maryland. “Their donors can continue to give to them. I can’t imagine the voters who are unemployed are sitting at home making contributions to candidates.”

U.S. House incumbents rarely lose. Their national reelection rate in 2018 was 91% — and it was 97% in the congressional election before that. The last Maryland congressman to lose reelection was Republican Roscoe Bartlett of Frederick County in 2012 — and he was defeated only after his district was redrawn by Democrats in Annapolis to include more Democratic voters.

Carter said she remains in the race and that she and her volunteers — wearing masks and gloves, and not standing close to voters — plan to visit the limited in-person voting centers open on primary day.

“I realize victory is a long shot,” she said.

Mfume, who says he was friends with Cummings for more than 40 years, was sworn in less than a month ago. But he previously held the seat for 10 years, stepping down in 1996 to lead the NAACP. Cummings won a special election to succeed him.

“I know the community, the community knows me,” Mfume said. “It’s been a part of my whole life.”

Since retaking office May 5, he said he has focused on Baltimore crime and trying to ensure there is sufficient aid for those enduring economic hardship because of COVID-19. He called last week for a prosecution “to the fullest extent of the law” in the death of George Floyd, a black man, at the hands of police in Minnesota.

Mfume’s challengers Tuesday also include Rockeymoore Cummings, the former Maryland Democratic Party chair who casts herself as her late husband’s rightful political heir. The public policy consultant said it is “absolutely my job to carry on Elijah’s legacy, and that is what I intend to do.”

Since the pandemic took hold in March, Rockeymoore Cummings has frequently appeared on social media and says her campaign has “been on the vanguard of how to do virtual campaigning. I actually think it’s enhanced my standing in the race.” She has alleged that Mfume is overstating his friendship with her late husband for political advantage, an accusation Mfume calls “sad.”

Other Baltimore-area incumbents in the primary are Democratic Reps. John Sarbanes and C.A. Dutch Ruppersberger of Baltimore County, and Rep. Andy Harris, whose district is made up of parts of Baltimore, Carroll and Harford counties, as well as the Eastern Shore.

Harris is Maryland’s only Republican U.S. House member. He is challenged on Tuesday by conservative Jorge Delgado, a former economic policy adviser to U.S. Sen. Cory Gardner, a Colorado Republican.

Jennifer Pingley, a nurse, and Mia Mason, a 20-year military veteran, are competing on the Democratic side. Allison Galbraith, who ran unsuccessfully in the 2018 primary, withdrew in April (her name will still appear on the ballot) citing family responsibilities and saying that COVID-19 “has created challenging circumstances for all of us.”