With a few days left before the Illinois primary, the Cook County state’s attorney’s race has already become the most expensive in Cook County history, with candidates raising  almost $16 million combined, which is more than double that of the 2016 primary.

While the two frontrunners have both been pulling in big bucks, the story of how they’ve come up with the money have been vastly different. Incumbent Kim Foxx has been funded by a steady stream of donations from the democratic establishment, while her strongest challenger Bill Conway has received regular cash dumps from his father William E. Conway, Jr. and large donations from members of the Carlyle Group, the investment firm co-founded by his father.

“A self-funded candidate like Conway changes the dynamics of a race completely … and that’s a big part of why there’s so much more spending  this time around than last time” said Michael Kang, a law professor at Northwestern’s school of law and expert on campaign finance. “That seems to be driving a lot of the spending. Foxx as the incumbent, especially this time around, has more of a name that they can draw money from national sources to fight off the Joneses.”

While Foxx and Conway’s fundraising was neck and neck during the fall when they were both still shy of their first million dollars, Conway’s began to pull away with the first donation of $500,000 from his father in August of last year. As of the this week, Conway’s campaign committee has raised triple that of Foxx.

Foxx’s top donors include: Fred Eychnar, president and CEO of Newsweb Corp.; Michael Sacks, chairman and CEO of Grosvenor Capital Management; and e-commerce billionaire Michael Rubin.

Scroll to see all donors from July 1, 2019, to March 10, 2020.

But unlike the other candidates, Foxx has also received major support from super PACs, which cannot coordinate with or give directly to a candidate and are not limited by how much they can raise or spend for or against a candidate. The Citizens United Supreme Court decision allowed such activity at a federal level, while state-level committees are subject to local regulation.

Illinois Justice & Public Safety PAC, a political action committee connected to New York billionaire George Soros, has spent nearly $940,000 to oppose Conway. Vote Liberation has also spent more than $110,000 on Foxx during the same period, according to the Chicago Tribune.

Soros also aided Foxx in 2016 and has long supported candidates focused on reducing racial disparities in sentencing, according to Politico.

William Conway was already his son’s biggest donor when he gave his first seven-figure donation to the campaign at the beginning of the year. Since his son’s committee was created last August, he’s donated $10.5 million dollars for the campaign.

He’s received no other donations in the millions, but his top ten donors include members of the Carlyle Group including: Allan Holt, a senior partner and managing director, Gregory Ledford, a senior advisor, and Peter Claire, a member of its board of directors. The Carlyle Group did not respond to requests for comment.

Scroll to see all donors from July 1, 2019, to March 10, 2020.

Foxx and Conway did not respond to requests for comment.

All this money has helped fuel dueling television advertising campaigns by both lead candidates, with Conway ads portraying Foxx as a crook and attorney for celebrities while ads supporting Foxx characterize Conway as a rich kid bankrolled by his father’s mysterious influences.

Conway’s father amassed one of the biggest fortunes ever made in private equity, which has provided fodder for the other candidates to link his campaign to the Carlyle Group’s ties to the military-industrial complex. The campaign has also been attacked for allegations of neglecting elderly patients and medicare fraud at the company’s for-profit nursing home chain HCR ManorCare, as recently reported by the Chicago Tribune.

When asked about the connection to ManorCare, Conway said he wasn’t familiar with the incident, telling the Chicago Tribune, “We all have relatives that we don’t agree with, but I’m certainly not going to sit here and disown my own father.”

Donna More, who also ran in 2016, sees herself as an independent free from the shackles of the Democratic party and corporate money. She hasn’t been able to crack the million dollar mark and has raised about $440,000. She gave $143,000 of that to herself. More’s top donors include Accel Entertainment, the biggest video gambling operator in the U.S.

“This is how I grew up in the Democratic Party, how it’s supposed to be done,” said More. “You raise money the old fashioned way. You go to people, you talk to them, you tell them what you believe in, and they believe in you and they contribute money. What we’ve come to in a lot of elections is — you either have to be part of a political machine or you have to know a billionaire. And I don’t think that’s the way you get the best candidates.”

Scroll to see all donors from July 1, 2019, to March 10, 2020.

While the super PACs are geared towards criminal justice reformers, Foxx has struggled to make her reforms focused on reducing prosecution of low-level drug offenses and theft to the forefront of the campaign as her opponents target her handling of the Jussie Smollet scandal.

The former “Empire” actor was recently indicted for the second time on allegations he staged a hate crime in January 2019, which has also helped stoke the controversy.

Despite the disparities in fundraising, recent polls show Foxx leading Conway 33% to 19.5%, though more than a third of voters — 37.5% — were undecided.

When “undecided” wasn’t an option, Foxx jumped to 48.2% and Conway grabbed 31.7%.