THE CROWDED DEMOCRATIC primary field in the Fourth Congressional District got a little less crowded Thursday morning when one of the candidates, Dave Cavell, announced he was suspending his campaign. But the exit by the former Obama speechwriter didn’t just shake up the September 1 primary for the open House seat, it put a spotlight on an electoral reform ballot question voters will be asked to decide in the November 3 general election.

Cavell said his decision to quit what had been a nine-way scramble for the Democratic nomination was motivated by a wish not to see one of the leading candidates, Newton City Councilor Jake Auchincloss, prevail as a result of other candidates with similar views splitting the support of like-minded voters.  

“There are many strong candidates to represent the people of the Fourth District,” Cavell said in a statement.  “Unfortunately, there is one candidate in this race who I believe has proven himself unfit to represent this District. In a crowded field without ranked-choice voting, I refuse to make it more likely that the people of our District, particularly Black and brown people, will be represented by someone we cannot trust.” 

Dave Cavell, who dropped out of the Fourth Congressional District race, threw his support to Jesse Mermell and said he wanted to stop Jake Auchincloss from winning the seat.

In November, voters will be asked whether the state should adopt ranked-choice voting for elections beginning in 2022. Under the voting scheme, in a multi-candidate race voters rank candidates in order of preference. The initial count considers the top choice of each voter. If no candidate wins a majority, the last place finisher is eliminated and the second-choice votes of his or her supporters are distributed to the remaining candidates. The process continues until a candidate clears the 50 percent threshold and is declared the winner. 

Supporters say ranked-choice voting ensures that candidates who get elected have broader support than those who win under the current structure, in which the candidate with the most votes wins, even if it is only a small share of the total vote. 

Backers of the Yes on 2 ballot question campaign say the crowded Fourth Congressional District primary is a textbook example of the flaws of the current system — and a perfect case for ranked-choice voting. Even with the field down to eight candidates, one of the Democrats could easily win the primary with less than 25 percent of the vote, which could be 20,000 votes or less. The primary winner will be heavily favored to capture the seat in November in the Democratic-leaning district.

Jake Auchincloss: A front-runner with a target on his back.

I said all along that it made no sense that I or anyone else could win 20 percent of the vote in the Democratic primary, go on and win in November, and represent all 750,00 people in that distinct even if only a small fraction of them cast ballots for us,” said Cavell.

Cavell said he was throwing his support in the race behind fellow Brookline resident Jesse Mermell, a former top aide to Gov. Deval Patrick with a liberal profile similar to his.  

The race for the slot Joe Kennedy is vacating to run for US Senate is hardly the first time someone could land a congressional seat in the state by capturing only a sliver of the vote. 

Two years ago, Lori Trahan narrowly won a 10-way Democratic primary for the Third Congressional District seat in the Merrimack Valley with just 22 percent of the vote. She easily captured the seat in the November election.

“This is it all over again, and it happens routinely in these crowded races,” said Greg Dennis, policy director for the Yes on 2 campaign, referring to this year’s Fourth District contest. 

Trahan joined a group that could be dubbed the 22 or 23 Percent Club. In 1998, Michael Capuano won a 10-candidate primary in what is now the Seventh Congressional District with 23 percent of the vote. And Ed Markey, now facing a tough primary challenge from Kennedy for the US Senate seat he won in 2013, landed in the US House in 1976 by winning a 10-way Democratic primary with just 22 percent of the vote. 

In 2016, Maine became the first — and thus far only — state to approve ranked-choice voting for statewide and congressional elections. Versions of the voting system are used in several cities across the country, including Cambridge, where it is used to elect the City Council and School Committee. 

The Yes on 2 campaign has enlisted a bipartisan roster of high-powered supporters. Former governors Deval Patrick and Bill Weld are two of the campaign’s seven honorary co-chairs, along with former Harvard president Lawrence Summers, former lieutenant governor Kerry Healey, Harvard professor Danielle Allen, Boston NAACP president Tanisha Sullivan, and Bain Capital co-chairman and Boston Celtics managing partner Steve Pagliuca. 

Despite the lineup of heavy hitters supporting the reform, the ballot question looks like anything but a sure thing to pass at this point. In a new statewide survey released today, the MassINC Polling Group found that voters are deadlocked on the question, with 36 percent supporting the measure, 36 percent opposed, and 27 percent undecided. 

“There’s a lot of people that haven’t made their mind up yet, but tied is not where you’d want to be if you’re the proponents of this question,” said Steve Koczela, president of MassINC Polling Group, which carried out the poll for WBUR. Koczela said winning ballot questions tend to start out with a high level of support, “which erodes away, and you hope it stays above 50 percent by the time of the election.” 

He said the no side is the default voters go with in a ballot campaign. “To change something you have to give people a reason, and right now people just don’t know what those reasons are,” Koczela said. 

The Yes on 2 campaign pointed to the fact that the question was viewed more favorably in the poll among the roughly two-third of voters who said they understood the ranked-choice voting system well. Among these voters, support increased to 52 percent versus 37 percent who were opposed. 

“The more they know about it, the more they support it,” Dennis said, highlighting the need for more voter education on the issue. “Our challenge will be, can we do that with enough people in the middle of a pandemic by Election Day?  I’m confident we can, but it will take an effort.” 

Cavell’s exit was unusual not because he threw his support to another candidate, but because he said he was motivated primarily by a strong wish to block one candidate from winning. Auchincloss has become a target of attacks from several rivals who have pointed to comments he has made on race and religious issues. 

Auchincloss did not respond directly to Cavell’s statement. 

While other candidates engage in political back-and-forth, Jake spent the morning in Fall River with endorsers Mayor [Paul] Coogan, Rep. [Carole] Fiola, and Rep. [Paul] Schmid, packing food for needy families and discussing his plans for an inclusive economic recovery,” his campaign spokeswoman, Yael Sheinfeld, said in a statement.