Outside political groups raised five times as much as the CTU and spent nearly three times as much, according to an analysis of campaign finance filings covering Oct. 1, 2025, through Oct. 15, 2026. Political action committees and independent expenditure committees spent a combined $8.1 million across the races. The filings show a sharp rise in campaign activity over the past three months.

More than one-quarter of that outside spending has gone toward opposing Hilario Dominguez, a former teacher and the union’s deputy political director who is running for board president. The spending against Dominguez exceeds four times the amount spent to support Jessica Biggs, a former Chicago Public Schools principal and another contender for the position.

Michael Sacks, a billionaire investor and longtime donor to Chicago political causes, has given $5.5 million to groups involved in the election. His newly formed Common Ground Collective super PAC has spent $3.7 million, including about half on digital advertising and production opposing Dominguez. Sacks also gave $400,000 to Biggs, who has attracted contributions from labor unions other than the CTU, former CPS leaders and business executives. Common Ground has not endorsed a presidential candidate.

The Illinois Network of Charter Schools’ political groups have spent $1.7 million supporting 19 candidates, while its INCS Action super PAC spent $450,000 opposing Dominguez. Jim Frank, a retired Winnetka executive and regular donor to charter school political efforts, has contributed $3.8 million to groups involved in the races.

The CTU and a political committee it funds have reported raising about $2.5 million and spending roughly $2.2 million. The union spent $4.3 million through two political committees in the 2024 school board races, with about half of that spending coming in the final month. CTU research director Pavlyn Jankov said the union expects to keep investing in the current election, while noting that it cannot match billionaire donors dollar for dollar.

Dominguez said the contest should be decided by voters rather than the largest spenders. “We didn’t go from mayoral control to go to billionaire control,” he said, arguing that organized voters can outweigh organized money.

Candidates themselves have raised $5.9 million since October 2025, including $3.5 million for the board president contest. The 20 district races account for the remaining $2.4 million; 15 are contested, and one Northwest Side race has drawn $292,062 in candidate contributions.

The spending is also unfolding amid a rift between the CTU and SEIU, which represents CPS support staff. The unions have diverged on 10 candidate endorsements, including the board president race, and overlap on five. SEIU-backed PAC chair Anthony Driver said his union supports candidates based on their positions and is spending to support candidates, not attack others.

The election is drawing attention in part because the board’s makeup could shape decisions about the city’s public schools and influence the political landscape ahead of Chicago’s February mayoral race. Some of the $12.7 million raised by three education-focused political committees could be used in that contest, according to Arnie Rivera, a former CPS chief operating officer who now leads the Chicago Education Alliance.