But Mr. Rauner, 61, survived a challenge from Jeanne Ives, a Republican legislator and Army veteran who took a hard-right stance on social issues and attacked him for being insufficiently conservative.
Mr. Rauner appealed for unity in a speech on Tuesday night, imploring Republicans, independents and Democrats to give him another term in office to institute needed change.
“Let’s work together to bridge the divide,” he said. “The election in November will be a choice, a clear choice, a choice between someone who will stand up to the machine and someone who has long been part of it. Between someone who will fight for hardworking families and someone who will protect the political insiders.”
Mr. Pritzker, who has donated close to $70 million to his own campaign, fell short of 50 percent of the Democratic vote, but still outpaced Chris Kennedy, a businessman and a son of Robert F. Kennedy, and Daniel Biss, a suburban state senator.
In an acceptance speech before a crowd of supporters here on Tuesday night, Mr. Pritzker, 53, called for universal health care, fair wages, protections for labor unions and the legalization of marijuana.
He vowed to be a champion for the needy, for children, and for immigrants who have come to Illinois seeking a better life.
“This campaign is about a fight for economic security, about jobs and wages,” Mr. Pritzker said. “I choose to fight for the struggling. I choose to fight for the black and brown communities across our state, for the one thing, the one and only thing you’ve asked for for so long — fairness.”
“Are you ready for a fight?” he said, drawing wild applause.
Mr. Pritzker and Mr. Rauner are fighting to lead a state with deeply entrenched problems. Whoever wins will have to contend with Illinois’s vastly underfunded pension systems; worries about residents fleeing the state; and a sagging economy downstate, where manufacturing jobs have disappeared, leaving many residents unemployed and financially struggling.
Both men have moved in elite Chicago circles of business and philanthropy for decades, yet they did not share a personal relationship. In an interview last month, Mr. Pritzker said he barely knew Mr. Rauner, and was better acquainted with his wife, Diana Rauner, who runs a public-private partnership focused on early childhood.
Mr. Rauner, a native of Chicago’s wealthy north suburbs who made a fortune as the chairman of a private-equity firm, presented himself to voters in 2013 as an outsider, a Harley-riding political newcomer with a folksy affect who would fix Illinois’s financial problems and make the state more attractive to companies.
Mr. Rauner’s tenure has been marked by a budget impasse that paralyzed Illinois, especially social-service agencies, arts organizations and public universities that depend on state funding. It was finally resolved last July when Democrats in the State Legislature overrode Mr. Rauner’s veto, ending the stalemate and passing a budget.
During his first run for office, he rarely mentioned social issues like abortion and managed to attract sizable support from independents and Democrats. As governor, he angered religious conservatives by signing a bill that expanded abortion coverage for women on Medicaid.
Last week, he vetoed a piece of legislation that would have required gun dealers to obtain state licenses, a move that was widely seen as an appeal to Republicans in rural downstate Illinois.
Ms. Ives, a member of the Illinois House, positioned herself as the true conservative in the race. But she trailed Mr. Rauner in fund-raising, raising $4 million to his $100 million. She criticized Mr. Rauner over abortion rights, immigration and his handling of a Legionnaires’ disease outbreak at a state-run veterans home that has left 13 people dead since 2015.
In the campaign’s final days, the Democratic Governors Association sneaked into the fray, running a television ad attacking Ms. Ives as “too conservative” — presumably a veiled attempt to give Ms. Ives a boost in the hopes that she could overtake Mr. Rauner in the primary.
In the closely watched congressional primary, the challenger, Ms. Newman, drew on Democrats’ appetite for more confrontational and liberal officeholders as she gave Mr. Lipinski the biggest scare he has had since he was elected in 2004.
Wielding support from an array of progressive groups, Ms. Newman assailed Mr. Lipinski, a conservative Democrat, for his opposition to such liberal priorities as abortion rights and the Affordable Care Act.
After attempting to ignore the challenge, Mr. Lipinski scrambled to put down the insurgency with a late blitz of commercials and mailers highlighting his more orthodox positions and roots in Chicago’s so-called Bungalow Belt.
He succeeded his father in the seat, which has sent a Lipinski to Washington since 1982. But the same southwest side and suburban Chicago precincts that were mainstays of the city’s Democratic machine are quickly evolving. A growing Hispanic population and the influx of upscale white voters have transformed what were once working-class Irish and Polish neighborhoods. The remaining, machine-aligned precincts in the city helped him compete against Ms. Newman.
“I would like Mr. Lipinski to have a very painful evening, so we’re going to wait,” Ms. Newman told supporters after taking the stage around 10:45 p.m. local time, adding only that she would say more on Wednesday.