Republican rivals are questioning the donation made to the selective enrollment school attended by Rauner's daughter.
Rauner's Republican primary opponents charge that Rauner made that donation in return for CPS officials admitting his daughter to an elite public high school.
''Absolutely not, this is just political muscling because we're winning the race,'' Rauner said.
The multi-millionaire businessman who lists his home address in Winnetka would not say where in Chicago his daughter lived when she attended the public Walter Payton Magnet High School between 2008 and 2012. Payton reputed to be among the best high schools, public or private in the country, with a waiting list of over seven thousand city teenagers.
''I'd like to know who didn't get in because his suburban daughter got in,'' said Senator Kirk Dillard.
The revelation that Rauner made a $250,000 donation to Payton comes on the heels of his conflicting statements on whether to lower or raise the minimum wage. His Republican primary opponents also demand answers about Rauner payments to Stuart Levine since convicted in the Blagojevich scandal and Rahm Emanuel, who made millions from a Rauner merger deal after Emanuel left the Clinton White House.
''He should just come clean and provide the voters with transparency and answers to all these questions,'' said Senator Bill Brady, who's also running for governor.
''There's nothing wrong with wealth but it's how you make it and how you use your wealth that's the story, Dillard said.
''I don't need a job and I can't be bribed or intimidated or influenced. I scare all the people in Springfield and in this race,'' Rauner said.
Rauner's daughter graduated from Payton in 2012. Since then, the family moved back to the Winnetka house, which is now listed as its primary residence.