Attendees at an Arlington voter forum check over a handout showing each speaker running to replace Rep. James Moran. (Michael S. Williamson/The Washington Post)

Canek Aguirre knows the positions of each of the seven Democrats running for Congress in his Northern Virginia district as well as anyone not working on a campaign. He has talked to most of the candidates.

But Aguirre, 29, can’t make up his mind about who will get his vote in the June 10 Democratic primary to replace Rep. James P. Moran (D-Va.).

“They’re all very similar, that’s one of the first things that jumps out,” he said, weighing his choices as he ate a meatball gyro at an Alexandria patio restaurant.

In a field in which all candidates call themselves progressive or liberal, support the Affordable Care Act and women’s reproductive rights, view climate change as a given and immigration reform as necessary, how can a voter decide who gets the nod?

The winner of the primary will probably beat Republican Micah Edmond and Libertarian Jeffrey Carson in November, given the overwhelmingly Democratic leanings of the 8th Congressional District, which encompasses Alexandria, Falls Church, Arlington and parts of Fairfax.

This is a district that gave Gov. Terry McAuliffe (D) and Attorney General Mark R. Herring (D) some of their largest margins of victory last fall. President Obama won 67 percent of the vote here in 2012. Given the power of incumbency, that means next week’s balloting could crown a new member of Congress for many years to come.

And yet Aguirre, who will soon start a new job in community relations for Anthem Blue Cross Blue Shield, cannot interest his friends in any of the candidates: front-runner Don Beyer, a former lieutenant governor and ambassador; Del. Patrick Hope ; state Sen. Adam Ebbin; Alexandria Mayor Bill Euille; talk show host Mark Levine; Virginia Tech professor Derek Hyra; or Lavern Chatman, former head of the Northern Virginia Urban League.

“They don’t even know there’s a race going on,” Aguirre said, shaking his head in frustration. “They’re young professionals like me, and the interest isn’t really there. They say ‘Ah, I’m not going to vote in the primary. I’ll wait until November.’ The problem with that is, it’s decided now.”

The typical Democratic primary voter in Northern Virginia is a retirement-aged white woman, campaign operatives say. Charilyn Wells Cowan of McLean is one of them. Like Aguirre, she is well-versed in the choices. And, like Aguirre, she doesn’t know whom she wants to back.

Cowan, who describes herself as “a concerned senior citizen,” took copious notes at a May 15 forum as she narrowed her choices to Beyer, Levine and Hope.

“Generally, I thought that Beyer had thoughtful, nuanced answers to many questions and seemed to fit the part,” she said. But she also is thinking of the future.

“Patrick Hope and Mark Levine are both young enough to be there awhile, and actually gain some seniority,” she said. For Beyer, 63, a victory “could be a capstone” to his career.

The candidates know that their similarities are making it hard for voters to separate them. In response to a moderator’s question last month, most identified as “Elizabeth Warren Democrats” — although Beyer said he is more in the mold of a “Hillary Clinton Democrat.”

At candidate forums, Hope often says: “Everyone up here is qualified to be your next member of Congress.”

Aguirre, who is Mexican American, previously worked for the Alexandria school system, helping at-risk students and their parents connect with school officials. He grew up in Southern California, where his mother supported the family as an elementary school teacher.

In 2007, Aguirre graduated from the University of North Carolina at Chapel Hill.

Education is highest on his list of priorities, he said, because he thinks that better-educated citizens will help the economy grow. Women’s reproductive rights and equal pay, he said, are “just basic.”

“I feel like that shouldn’t even be an issue,” he said. “Immigration is extremely important because it ties into the economy. We need this global influx.”

He has listened closely at campaign events for discussion of how to address Northern Virginia’s steep cost of living — a theme that threads through many conversations in the 8th District, and is particularly relevant to a renter like Aguirre.

He shares an apartment with his girlfriend in the Delray area of Alexandria, near a bus line that he used to get to his job before he could afford a car. When his girlfriend was briefly out of work, they struggled to cover the rent.

And as a volunteer for Tenants and Workers United, a grass-roots social action organization based in Alexandria’s Arlandria section, he has met much-lower-earning residents, who are worried about being displaced by the gentrification that accompanies redevelopment.

The candidates met for a final debate Friday night in Arlington. One last time, Aguirre asked his friends if they wanted to attend.

“I try not to push them too hard. I try to sneak it into the conversation,” Aguirre said. “I’m not even trying to convince them of one person or another. I’m just trying to convince them to go listen.”

But no one was willing. So, again, he went alone. He had narrowed his choices to Beyer, Levine and Chatman, but concluded after a lively, 90-minute session that Levine did not seem collaborative enough. So now he’s down to two.

Beyer is “the most polished,” Aguirre said. Chatman, who is African American, caught Aguirre’s attention “because she’s so different.”

“She has a lot of community and life experience,” he said. “When you consider the makeup of Congress in general, there is a lack of different faces.”

He sat near the back of the auditorium, in a crowd of more than 300, taking notes on his phone.

“Just things I want to think about, to remind myself,” he said. “I’m very torn.”