...Rauner has positioned himself as a change agent while avoiding details that might turn off voters from either party. He sticks to a narrow script, advocating term limits and lower taxes without offering many specifics about what he would do differently from the “knuckleheads” (his term) currently running state government. Nor, as of presstime, has he discussed in any real detail some topics considered standard for politicians, such as his religious beliefs (if any), his family (beyond his wife and his maternal grandfather), or his stance on such hot-button social issues as abortion, gay marriage, drug policy, crime reduction, or capital punishment.

Around this time, a 20-something brunette named Diana Mendley signed on to Rauner’s firm as an associate....In 1989, while working at GTCR, she married a fellow Stanford business grad from Highland Park, Lewis Ingall, whose father ran the pediatrics department at Evanston Hospital.

But back to Rauner’s wife, Beth. In the summer of 1990, she learned a devastating secret. According to court documents—obtained by Chicago and first reported by Business Insider this past May—Beth “discovered a paramour existed.”

That September, Beth, her husband, and their three young children moved to a large house in Winnetka. Two months later, Rauner left, moving first to an apartment in Evanston and then to one in Wilmette.

(Rauner's divorce) proceedings dragged on for more than two years after Beth filed to end the decade-long marriage, in part because Rauner initially took the unorthodox step of forgoing a lawyer and representing himself in the divorce.

In May 1992, as settlement negotiations ground on, Beth’s lawyer filed a temporary restraining order against Rauner to stop him from buying more houses. According to Beth’s affidavit, Rauner had told her he was trying to buy a new home where “he intended to reside with his girlfriend.” The affidavit continues: “I fear that Bruce will enter into a contract to purchase an expensive home, which he will then decorate and furnish at great expense, causing dissipation of assets [and] irreparable harm to my rights and those of our minor children.”

VeriFone is also a favorite of the Quinn campaign because it outsources much of its manufacturing to China, Singapore, and Brazil, providing Quinn with a sound-bite-ready example of how Rauner has hurt local workers. Quinn has also repeatedly criticized Rauner for the job cuts that typically follow the consolidations at the core of GTCR’s profits. And expect him to make more hay with allegations raised during the primary that GTCR plundered nursing homes, causing care to deteriorate and residents to die. “Bruce Rauner makes Mitt Romney look like Gandhi,” insists Doug Ibendahl, the former general counsel of the Illinois Republican Party. (In a televised debate in March, Rauner called ads citing the nursing home allegations “an outrageous political attack, taking advantage of a death or suffering of a family to score political points.”)

And scrutiny there would be. Recall the Business Insider story, titled “Illinois Gubernatorial Candidate Divorced in 1993 After Alleged Affair.” (Rauner’s campaign issued no response.) And the Crain’s Chicago Business report that he had “clouted” one of his daughters into Chicago selective enrollment high school Walter Payton College Prep, despite the fact that she reportedly did not meet the entrance requirements. (Rauner told me in May 2013 that “we didn’t do anything inappropriate whatsoever.”)

There had already been bad press involving another of Rauner’s children. In 2010, Eric, then 21, got arrested for trying to rob a Walgreen’s drive-through in Missoula, Montana. He gave a pharmacist “a note threatening to blow his head off unless he handed over prescription painkillers, according to charging documents in the case,” reported the Daily Missoulian. The paper further reported that he told authorities that he was drunk at the time and addicted to pills. Originally charged with felony robbery, Eric, who had been unarmed, pleaded guilty in July 2012 to an amended charge of felony criminal endangerment and received a three-year deferred sentence.