Should Ocasio-Cortez’s upset have Michael Capuano worried?

Michael CapuanoDavid L. Ryan/Globe Staff/File 2017

A woman of color challenges an entrenched white male US representative more than 20 years her senior in a Democratic primary in an urban district where the majority of the population is made up of racial minorities.

In New York City on Tuesday, 28-year-old Alexandria Ocasio-Cortez, a Boston University alumna, pulled off the greatest upset yet in the 2018 election cycle by defeating Representative Joe Crowley in the primary for the district that includes parts of Queens and the Bronx.

On Sept. 4, Boston City Councilor Ayanna Pressley, who also attended BU, will attempt to repeat that success, over Representative Michael Capuano, a 10-term Democrat, in the primary for the Seventh District, which includes Somerville, Chelsea, Everett, Randolph, half of Cambridge, one-third of Milton, and the majority of Boston.

Right on cue last night, Pressley tweeted a picture of herself with Ocasio-Cortez and offered congratulations. Hours later, Ocasio-Cortez responded with her own plea: “Vote her in next, Massachusetts.”

Ayanna Pressley.Katherine Taylor for The Boston Globe/File 2018

But while there are many similarities between the two contests, there are also some key differences. No congressional race can ever serve as a perfect point of comparison to another: These districts are different, election rules can be different, and, of course, the candidates are very different.

And that’s why Capuano might be less scared Wednesday than many Democrats and prognosticators are saying he should be.

For starters, Crowley, the fourth-highest-ranking Democrat in the House, had a reputation as somewhat moderate — at least for a New York City Democrat. He once served as the chairman of the New Democrat Coalition, a group that describes itself as “pro-economic growth” and embracing “fiscally responsible politics.” There was some significant room for Ocasio-Cortez to run to Crowley’s left in this campaign.

In the context of the Boston race, Capuano is generally more liberal than Crowley. He’s been a member of the Congressional Progressive Caucus since he came to the US House in 1999, and nonpartisan studies of their respective voting records show Capuano as consistently to the left of his recently defeated colleague.

“In the 7th District here in Massachusetts, Mike is an unwavering fighter for progressive values who is taking on Donald Trump at every turn and working hard for the people he represents,” Capuano press secretary Audrey Coulter said. “And he is not taking anything for granted in this campaign — and never has in any election.”

Along those lines, Ocasio-Cortez and Pressley don’t necessarily embrace the same ideology.

Ocasio-Cortez is a Democratic socialist and former organizer for Senator Bernie Sanders’ campaign. Pressley was a backer of Hillary Clinton in the 2016 Democratic presidential primary, and it’s worth noting that she’s taken some criticism for not yet articulating how her policies would be different from those of Capuano.

When it comes to the issue of immigration, the lines were clear in New York. Things are more complicated in Boston.

Pressley, like Ocasio-Cortez, has called for defunding the Immigration and Customs Enforcement Agency. But when Ocasio-Cortez spent her final weekend before the primary in Texas at a migrant detention center, Capuano was there as well.

Ocasio-Cortez and Pressley also bring different personalities to voters. Ocasio-Cortez was a bartender just a year ago, ran as a socialist, and has never run for office before. Pressley was the first black woman ever elected to the City Council, already represents some of the district she hopes to serve in Congress, and she was on the staff of then-US Senator John F. Kerry.

“The job description for representatives in Congress has changed,” Pressley said in a statement Wednesday morning. “In deep blue districts like New York’s 14th and the Massachusetts 7th, voters are asking for more than a reliable vote — they are asking for committed, activist leadership.”

As for the districts themselves, they are somewhat similar for an urban congressional district. Nearly 75 percent of the population in the New York district are minorities, either black, Asian, or Hispanic. In the Seventh District of Massachusetts, about 58 percent are minorities, but whites make up a majority of the voting population. That might not seem like not much of a difference, but consider the factor of turnout.

The primary in Massachusetts — scheduled for the Tuesday after Labor Day — could be just as a low-turnout affair as the race in New York, which brought about 30,000 voters to the polls.

And low voter turnout is one reason why US Representative Seth Moulton, a Salem Democrat, cautions against reading too much into the upset in New York.

“It is hard to draw national conclusions based on one low-turnout primary,” said Moulton, who remains neutral in Capuano’s race, to reporters Wednesday.

In the end, however, one thing is for certain: The surprise win in New York City on Tuesday night will probably bring renewed attention to the Boston race. And it’s hard to see how Pressley and her supporters don’t use this New York upset to her advantage.