The vote on Tuesday will almost certainly determine who will succeed former Representative David Cicilline, and could hold clues to what voters are looking for in the run-up to 2024.Days before a Democratic primary that will almost certainly decide who represents her in Congress, Linda Vaughan Dubois of Rumford, R.I., still had not decided on a candidate.“There’s so many,” she said at a recent meet-and-greet at an East Providence sports bar for Gabriel Amo, a Rhode Island native who worked in the Biden and Obama administrations and is one of 11 Democrats competing in the race to represent this deep-blue district in the country’s smallest state.Not wanting to “waste” her vote on a candidate who had no chance of winning, Ms. Vaughan Dubois, an intensive care nurse for infants who described herself as a moderate, said she was tracking down each of her top candidates to see what they were like in person.As Rhode Islanders return from their state’s well-loved beaches after the long Labor Day weekend, they will cast votes on Tuesday in a special primary election to determine who will replace former Representative David N. Cicilline, the seven-term Democrat who stepped down in May to become president of the Rhode Island Foundation.Gabriel Amo speaking to Linda Vaughan Dubois at a campaign event last week. Ms. Vaughan Dubois said she was tracking down each of her top candidates to see what they were like in person.Sophie Park for The New York TimesHis resignation, a surprise to much of the Rhode Island political world, gave rise to a crowded and chaotic contest during an otherwise sleepy summer political season. With 11 Democrats and two Republicans comprising a historically diverse field, the candidates regularly bump into one another at community festivals, ice cream socials, meet-and-greets and more as they try to prove themselves to voters.“It was like with the Patriots when Tom Brady left,” said Rich Luchette, a political strategist who advised Mr. Cicilline for almost a decade. “Everybody who was sitting behind Tom Brady felt like they should be the starting quarterback.”The fate of the seat in Rhode Island’s solidly blue First Congressional District almost certainly will not change the balance of power in the House, now controlled by Republicans. But the outcome of the election, which has pitted factions of the Democratic Party against each other, could hold clues about what Democrats are looking for in the run-up to next year’s elections, particularly in a state where former president Donald J. Trump over-performed in 2020.The race — and its diverse field — “reflects the rapidly changing nature of the Democratic Party nationally,” said Wendy Schiller, a professor of political science at Brown University. “There are a lot of groups that have been excluded from power that are now vying for power successfully, and you wonder how it can all be harnessed” to drive voter turnout next year.While there has been no independent public polling indicating who is favored to win, two candidates have emerged as leaders after a series of controversies that have shaken the race.Aaron Regunberg, a progressive former state representative widely seen as the front-runner, is backed by Senator Bernie Sanders of Vermont and Representative Alexandria Ocasio-Cortez of New York. Mr. Amo, a more centrist Democrat who is seen as a top alternative to Mr. Regunberg, has been endorsed by the Congressional Black Caucus, the former White House chief of staff Ron Klain and former Representative Patrick J. Kennedy, who represented the district before Mr. Cicilline.Senator Bernie Sanders headlined for Aaron Regunberg, to the right of Mr. Sanders, at a rally last week.Sophie Park for The New York TimesState Senator Sandra Cano has attracted a broad range of local endorsements. And Lt. Gov. Sabina Matos, who began the race as the only candidate who had won a statewide election, may still be in contention despite a scandal related to forged signatures on the nomination forms she filed to run.That was just one measure of the turbulence of the race. Don Carlson, another Democrat who had sought the nomination, dropped out just nine days before the primary. He suspended his campaign after an investigative report by WPRI, a Providence news station, found that Williams College had asked him not to return to teach there after he was accused of sending a text to a student in which he “suggested a relationship modeled on a website where people can pay to go on dates.” He has sought to clarify his conduct.Whoever wins the most votes in the Democratic primary on Tuesday is virtually assured of winning the general election. But with so many candidates dividing the vote, and no independent public polling, political observers say it’s difficult to predict how the election may go and how close it will be. Mr. Cicilline has stayed out of the contest, declining to throw his support behind any candidate.“It’s been rough,” Ms. Matos said. “I knew this was going to be a tough campaign. It has been really hard. But you know, it is worth it.”Lt. Gov. Sabina Matos saw her campaign slump after criminal investigations were opened into fraudulent signatures on her nomination papers. Sophie Park for The New York TimesIn East Providence, Ms. Vaughan Dubois said she was deciding between Mr. Amo and Mr. Regunberg, and above all was looking for someone who had “some experience” and could “play with the big boys — who don’t play nice.”That is at the heart of Mr. Amo’s pitch to voters, which emphasizes his professional background and his Ocean State roots. He frequently brings up his experience serving two presidents in the White House and former Gov. Gina Raimondo, now the U.S. secretary of commerce, in the Rhode Island State House.“People here in Rhode Island deserve a congressperson who can get the job done,” Mr. Amo said in an interview. “They want people who are not running to make a point. They want effectiveness.”Mr. Amo, a more centrist Democrat, is seen as a top alternative to Mr. Regunberg.Sophie Park for The New York TimesHe said that Mr. Regunberg would “go to Washington and grandstand to make a political statement.”Mr. Regunberg dismissed the attacks as expected in the final week before an election. He has criticized Mr. Amo for accepting contributions from corporate lobbyists.Mr. Regunberg has pledged not to accept corporate PAC or lobbyist money, and, as a former state legislator and activist, has made the case that he would be a liberal leader in Washington in the mold of Mr. Sanders, who headlined a rally for him last weekend.“This is a district that can support someone who’s actually going to organize” and push progressive policies in Washington, Mr. Regunberg said at the rally, where he addressed around 650 attendees — including young families, people donning “Bernie” merch and supporters from nearby Massachusetts — who had lined up on the sidewalk outside a historic theater in Providence to see him and Mr. Sanders.Although there has been no independent public polling indicating who is favored to win, Mr. Regunberg is widely seen as the front-runner.Sophie Park for The New York TimesLike Mr. Cicilline, who led the House Judiciary subcommittee on antitrust, Mr. Regunberg said corporate power was at the root of numerous political and economic crises, from climate change to prescription drug pricing, and the main issue for the Democratic Party to show voters it is taking on in order to win back control of Congress and re-elect President Biden in 2024.“2024 is an existential-threat-to-our-democracy kind of election,” Mr. Regunberg said in an interview at a vegan bakery in Pawtucket, R.I. “Substantively, we need to be taking on corporate power. But I also think, politically, it’s really important that we be showing that we’re the party that’s standing up for regular people.”But Mr. Regunberg also faced controversy during his campaign after his father-in-law, a top executive at the investment firm Janus Henderson, created and invested $125,000 in a super PAC on his behalf.Ms. Matos filed a complaint with the Federal Election Commission, accusing Mr. Regunberg of violating campaign finance law by coordinating with the super PAC. Mr. Regunberg has denied any wrongdoing.Ms. Matos, a moderate once seen as the front-runner in the race, saw her campaign slump after she was engulfed this summer in multiple criminal investigations into the fraudulent signatures on her nomination papers. Still, she maintains support from the Congressional Hispanic Caucus and a number of local unions.The race has spurred several historic bids, including seven candidates who would be the first person of color to represent a state whose Hispanic or Latino population increased 40 percent from 2010 to 2020, and three who would be the first Democratic woman.State Senator Sandra Cano has attracted a broad range of local endorsements.Sophie Park for The New York TimesMs. Cano, a Colombian American state senator who has worked her way up through local government, said the diversity reflects “the progress that our community is making” and is “something that we need to celebrate.”Ms. Cano immigrated to the United States from Colombia under political asylum, an experience she said has been at the core of her desire to be involved in politics.“My democratic values have always carried with me,” she said, “because I came from an unhealthy democracy.” More