A Chicago-based family of billionaires, with close ties to Chicago mayor and former Obama chief of staff Rahm Emanuel, were revealed as the secret donors behind a series of anti-Donald Trump advertisements.

A report from the Federal Election Commission, revealing donors to the Our Principles PAC, shows Chicago’s Marlene Ricketts was the single biggest donor to the group headed by former Mitt Romney adviser Katie Packer.

According to The Hill, the PAC spent up to $4 million fighting Donald Trump in the first three GOP primary states.

As this primary cycle began, the Ricketts gave $5 million to a super PAC supporting Wisconsin Governor Scott Walker’s now failed bid for the White House. The family also gave ten thousand each to PACs working to elect both Sen. Ted Cruz and Sen. Marco Rubio. Now the FED report reveals that Ricketts gave an additional $3 million to the anti-Trump PAC.

The Ricketts family are the owners of the Chicago Cubs and recently reached what many local residents feel is a sweetheart $500 million deal with Chicago Mayor Emanuel to renovate the Cubs’s Wrigley Field, the second oldest stadium in Major League Baseball.

When the deal was reached in 2013, Mayor Emanuel hailed the agreement as a balm for the city’s increasingly failing economy.

“This framework allows the Cubs to restore the Friendly Confines (of Wrigley) and pursue their economic goals, while respecting the rights and quality of life of its neighbors,” Emanuel said in a statement.

But it has been a deal locals are increasingly unhappy with. Many Chicagoans feel that Rahm Emanuel gave away the store to the Ricketts family, and that dissatisfaction came to the forefront when, in January, the Cubs announced plans to widen sidewalks out into the streets around a ballpark entirely surrounded by businesses and homes.

Emanuel was urged by members of the city council as well as Wrigleyville residents to put an end to the Cubs’s plans to further restrict the roads and streets around the ballpark.

The mayor’s reputation has taken a beating in a city losing its population and tax base, fraught with closing schools and a rising murder rate, and bedeviled by months of Black Lives Matter protests over corruption in its police department. In fact, a recent poll found Emanuel’s approval rate at historic lows.

The Chicago Tribune poll from earlier this year found only 27 percent of respondents approved of the mayor’s leadership and performance, while a whopping 63 percent disapproved. The same poll found 55 percent agree that a new law should be passed in the state legislature to allow for a recall of Chicago’s mayor.

Emanuel’s reputation has been especially damaged by his failed handling of the Laquan McDonald shooting. The embattled mayor has maintained since the beginning of the controversy over the 2014 death of the 17-year-old African-American teen that he had little knowledge of the shocking police dash cam video of the shooting. But in January, it was shown that his office was fully aware of the contents of the video all along.

Many Emanuel critics have claimed the mayor kept the damning dashcam video of the death of the teen under wraps to avoid a raging controversy just as he was trying to win his first re-election campaign early in 2015.

Following the release of the video, Chicago erupted in months of protests that stretched from October into the new year.

Follow Warner Todd Huston on Twitter @warnerthuston, or email the author at igcolonel@hotmail.com.