The insurgency was sparked by the stroke of a pen.

Gov. Bruce Rauner’s signing of House Bill 40 in September expanded public funding of abortion in Illinois, alienated a huge portion of his Republican base and spawned a challenger who hopes to make him the state’s first incumbent governor to lose a primary contest in four decades.

“When he did it, he stabbed me in the heart,” Palos Hills voter Jim Hilton said at a rally for Rauner’s primary rival. “I don’t have the words to truly express the disgust that I feel for what he did.”

State Rep. Jeanne Ives has built a grassroots campaign to unseat Rauner by stoking that outrage, a growing disenchantment with the governor that has included his public split from the conservative Illinois Policy Institute — whose staffers briefly populated top levels of his administration — and the ignominious title of “The Worst Republican Governor in America” that Rauner received in the fall from the conservative National Review Magazine, which tied the knot Friday with its formal endorsement to Ives just four days before Tuesday’s primary.

Jeanne Ives

Jeanne Ives, Illinois Republican gubernatorial primary candidate. | Rich Hein/Sun-Times

“It was the ultimate betrayal,” Ives said of the governor’s signing of the abortion bill. “It was the moment when my colleagues started calling and saying someone needs to get in this race. There will be a reckoning.”

Rauner denies the claims of betrayal that earned him the nickname of “Benedict Rauner” and the label of RINO — Republican in name only.

And he makes no apologies.

“I said four years ago, and it’s always been true,” he told the Chicago Sun-Times while campaigning in the final week before the primary. “I support a woman’s right to decide. I don’t focus on social issues, never have. I’m focused on what unites us: lower taxes, more jobs, ending corruption, and term limits.”

Publicly, Rauner has all but taken his re-nomination as a given, instead talking up a potential general-election matchup with billionaire Democrat contender J.B. Pritzker while taking every opportunity to blast Illinois House Speaker Mike Madigan, the governor’s political archenemy. Most polls have backed Rauner up, showing him with a comfortable, double-digit lead over Ives.

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“What we are focused on is winning in November against Pritzker and Madigan and our message is a unifying message,” Rauner said. “Everybody wants lower property taxes. Everybody wants the income tax back down. Everybody wants to end the corruption by getting term limits. That’s how we’re going to win.”

But with a new survey suggesting that Ives had crept up within 7 percentage points of Rauner, a new round of television ad buys from the governor’s campaign on Friday suggested Rauner could be feeling the heat as one of the most vulnerable sitting governors in the country.

Gov. Bruce Rauner | Sun-Times file photo

Rauner, who made his fortune as a private equity manager and venture capitalist, has poured more than $57 million into his campaign over the last two years, dwarfing Ives’ war chest. The Wheaton Republican had just $1 million in her campaign fund last month, with $500,000 coming from Lake Forest businessman Richard Uihlein — a former Rauner supporter to the tune of $2.6 million, who flipped to the challenger’s side.

That cash helped Ives air a controversial TV ad featuring actors playing a Chicago Teachers Union member, a Women’s March participant, a man railing against illegal immigrants and an apparently transgender person. Ives, who has called gay marriage “completely disordered,” was slamming Rauner for signing bills that limit local law enforcement cooperation with federal immigration authorities, and that allow transgender people to change the sex listed on their birth certificates.

The ad was panned from both sides of the aisle as highly offensive, but it earned her national notoriety and didn’t hurt her fundraising. Soon after the provocative spot aired, Uihlein gave another $2 million to her campaign.

Ives also got back-door support last week in the form of a TV ad released Thursday by the Democratic Governors Association, which attacked her as “too conservative” — a criticism that she wears as a “badge of honor” over a governor she has painted as too moderate, campaign spokeswoman Kathleen Murphy said. The video seemed to be a thinly veiled booster by Democrats for Ives over Rauner in the primary because “she’d be crushed in the general election,” one Republican operative said.

Rauner campaign spokesman Will Allison accused Democrats of meddling to support “Madigan’s favorite Republican Jeanne Ives.”

Ives has hammered Rauner as caving to Madigan. She’s also pounced on the governor for his handling of the Legionnaires’ disease outbreak at the veterans’ home in Downstate Quincy, a crisis that has left 13 dead since 2015. Rauner has since appointed one of his top administrators to oversee the state response.

“We’re working hard. We’re going to keep our veterans safe,” Rauner said.

For his part, Rauner has touted “historic change” made under his administration, citing education funding reform and taxpayer savings via changes to government operations and Medicaid.

He claims a second term would be “transformative” for the state, but acknowledged Madigan has been a roadblock to the change Rauner promised when he first ran. He has clashed with the powerful speaker at every turn, with their wrangling leading to a two-year budget impasse that ended with an agreement including a state income tax increase — a concession Ives says she would work to repeal.

Rauner also recently vetoed a bill that would require gun dealers to obtain state licenses. He said his team took two weeks to study the bill before making a call, but Ives and other opponents accused him of timing the veto a week before the primary to bolster his conservative cred.

The candidates’ differences in their pocketbooks are as stark as their differences on the campaign trail. At a protest outside a Planned Parenthood facility in Flossmoor — one of dozens of campaign stops in the month leading to the primary — Ives shared a deeply personal story of describing how she went against doctors’ recommendations to abort her fifth child, who died soon after birth in 2002 due to a genetic abnormality.

Jeanne Ives, who is challenging Gov. Bruce Rauner in the Republican primary, held a small rally supporting her Right To Life agenda, outside the offices of Planned Parenthood in Flossmoor, in February. | John Booz/for the Sun Times

It’s testimony that hits home for her far-right base.

“It demonstrates a vulnerability and an openness that you don’t see on the other side,” Ives supporter Pastor Ceasar LeFlore said at the roadside rally, which drew a few dozen supporters on a cold, February morning. “It helps me to understand what her convictions are.”

By contrast, Rauner — tied up in official business across the state — made just a handful of campaign stops in the month before the primary. He spoke at a digital marketing firm in Naperville last week, and shook hands at an upscale lunch restaurant, sticking to regular talking points and riffing about his youngest daughter urging him not to run for governor in 2014 because she didn’t want him to end up in prison like four of the state’s previous nine governors.

“Changing the culture in state government has been extraordinarily difficult. When I started, I was 6-foot-8 and had a full head of hair,” Rauner joked.

Gov. Bruce Rauner talks to a diner at Hugo’s Frog Bar in Naperville on March 13, 2018. | Mitchell Armentrout/Sun-Times

Despite the intra-party mutiny — Rauner wasn’t even able to secure the support of his hometown New Trier Township Republican Organization — the sitting governor has a lock on most establishment endorsements.

“Bruce Rauner has shown a fierce commitment to fighting against the entrenched bureaucracy and special interests that have controlled Springfield for decades,” Cook County Republican Committee Chairman Sean Morrison said. “Gov. Rauner is the best equipped person to continue to lead this fight for reform.”

History could be on Rauner’s side.

If he loses on Tuesday, Rauner will be the first Illinois governor seeking re-election to lose a primary in 42 years — and the first GOP governor in 90 years.

But the potential of an Ives upset is not without precedent. In 1996, polls showed former state Rep. Al Salvi trailed then-Lt. Gov. Bob Kustra by 20 points for the Republican nomination for U.S. Senate, before Salvi’s shocking primary win. Salvi went on to lose the general election to Dick Durbin, but he thinks Ives could fare well against a weakened Democrat.

“The stars are aligning for her,” Salvi said.

He and other Ives supporters weren’t fazed by Rauner’s seemingly limitless campaign funds.

“It reminds me of little David facing a Goliath,” Pastor LeFlore said. “All it took was one stone.”