Downtown Ald. Brendan Reilly formally announced his intent Wednesday to take on Cook County Board President Toni Preckwinkle in the March 2026 Democratic primary, arguing “Cook County government is broken and is long overdue for change.”

His entrance is not a surprise. Reilly, 53, had first floated his interest in the role back in April and made no secret in recent weeks that he was passing petitions to take on Preckwinkle, the four-term incumbent who also heads the Cook County Democratic Party.

In an interview Wednesday at his River North campaign headquarters, Reilly suggested he would be running to Preckwinkle’s right. The lifelong progressive who has led the county board since 2010 has run up the county’s budget with little to show for it, Reilly said.

County voters “want to get government back to common sense solutions that address their everyday problems,” Reilly said. “They’re tired of the ideological battles and opining on international and global policy when we’ve got our own dumpster fire right here at home.”

Among those dumpster fires, Reilly said, are continued public safety struggles, rising budgets and property taxes, and “boondoggles” like the technology upgrade that has fueled late property tax bills and led to cost overruns in the tens of millions of dollars.

Reilly describes himself as an independent Democrat who has battled with all four mayors he has served under since joining the Chicago City Council. Elected to represent the 42nd Ward in 2007, Reilly argues he has helped fuel the success of downtown Chicago and would extend his business and development savvy countywide to create more affordable housing and broaden the county’s tax base.

Preckwinkle, he said, had shortchanged the Cook County State’s Attorney’s Office and Sheriff and pushed criminal justice reforms that let violent criminals back out onto the street.

In all, she did not put “nearly enough weight on the cost to victims and their families” and was “more focused on providing additional rights and security for those accused of committing violent crimes,” Reilly said. “To me, that’s problematic.”

He would boost budgets for both top prosecutor Eileen O’Neill Burke to beef up attorney staffing and for Sheriff Tom Dart to double down on its efforts to expand the public safety network he’s established throughout the county and assist the Chicago Police Department.

Reilly faces hurdles. Preckwinkle has been able to count on the support of progressive allies and public sector unions, and her position as the head of the county Democratic Party, to bolster her recent campaigns. Reilly said, though, he expects lots of fellow Democrats to defect.

Several party colleagues he declined to name until he begins rolling out endorsements in the coming weeks “have expressed their own concerns about Toni’s leadership and want to find ways to be helpful to my campaign. I have a number of my colleagues on the City Council… whose organizations are out circulating petitions on my behalf as we speak, and they’ve been having a really easy go of it. We’ve already secured more than enough good signatures to get my name on the ballot for County Board President and we’ve only been doing this for three weeks.”

This is not the first time he has contemplated a run for higher office. He floated a potential congressional run against U.S. Rep Danny Davis.

But Reilly said his recent cold turkey sobriety had granted him renewed focus and energy and given him more time to think about his political future. He has turned to exercising five days a week for his endorphin fix and estimates he’s lost 40 pounds over the past year and a half.

“I got results back on a pretty scary liver enzyme test” about 16 months ago, Reilly said. He stopped drinking for a couple months to get retested. “During that time, I had done a lot of soul searching and realized that alcohol was no longer a good fit for me. It had never interfered with my professional responsibilities, and that had always been my benchmark. But I did see that it was starting to creep into my personal life and that I was starting to lean on it too much to handle day-to-day stress at the job.”

“I only wish I’d maybe made that decision a few years sooner,” he said. “If my opponent wants to go there, I guess she could. But the bottom line is, I’ve made this change. I’m sticking to it and I’m a much better person for it.”

Raised in Hanover, New Hampshire and a graduate of Hobart College in upstate New York, Reilly followed his family to Chicago after his father, Dr. Brendan Reilly, became chief of medicine at Stroger Hospital.

He began his political career working for Mike Madigan, who at the time was the Minority Leader in the Illinois House. Reilly started his six-year stint in Madigan’s office as an environmental policy analyst and appropriations staffer helping crunch budgets. After roughly a year, he became Madigan’s communications director and heading up communication for the Democratic Party of Illinois.

Madigan, an emerging political powerhouse, helped win back the majority for Democrats at the time. “We removed dozens upon dozens of House Republicans from office during my time there, and we have quite a track record of success in making big gains for Democrats across the state,” Reilly said.

Reilly said he had no knowledge of the corruption Madigan would be later convicted of. “I had a very narrow role there, and certainly when I was working for the organization, I had no knowledge that anything like what we’ve read about in the papers was going on… this was nearly 30 years ago.

He went on to become spokesman for Paul Vallas’ unsuccessful gubernatorial primary campaign in 2002, and had recently left a job as AT&T’s Midwest vice-president of public affairs with a stock payout when a friend recommended he take on longtime downtown Ald. Burt Natarus in the 2007 municipal election.

Madigan and then-Mayor Richard M. Daley supported Natarus.

Reilly refused to accept campaign contributions from developers, alleging Natarus was too close to them. With the backing of a bipartisan campaign team and a leg up from SEIU, which was rallying against an ordinance allowing big box stores into city limits, Reilly upset Natarus and has not been meaningfully challenged for the spot since.

After establishing what he said was a more transparent zoning process, Reilly began accepting developer contributions again. He expects downtown business interests to support him in this race and possibly, to win some support from unions.

“Obviously some folks are going to want to stick with the incumbent. That’s typically a safe bet. I’d argue it’s a bad bet this time.”