CHICAGO (CBS) — It’s not even prime political season yet, but one ballot issue is already getting millions of dollars in funding from the governor himself.

CBS 2 Political Investigator Dana Kozlov on Wednesday dug into Gov. J.B. Pritzker’s multimillion-dollar donation.

Pritzker talked about many issues on the campaign trail. But the one he talked about a lot was getting a graduated income tax passed.

Now, it’s go-time for the governor and that issue. It’s on the ballot in November, and it’s such a priority that Pritzker just donated $5 million of his own money to a ballot initiative committee called “Vote Yes for Fairness.”

The committee solely exists to “support the proposed Graduated Income Tax Amendment to the Illinois Constitution.”

“Look, it was important to me to step up and support something that I’ve been talking about since day one of my campaign,” Pritzker said.

So far, Pritzker is the only donor to “Vote Yes for Fairness.” But the billionaire isn’t the only wealthy governor to throw some really big money toward causes he supports – according to the website for Illinois Sunshine, Gov. Bruce Rauner did too.

Rauner gave $2.5 million in 2016 to Liberty Principals PAC to support “liberty-oriented policies and candidates.”

Is $5 million Pritzker’s upper limit?

“I don’t know,” Pritzker said.

State Rep. Dave McSweeney (R-Cary) opposes the graduated income tax. He believes the other side will also spend millions.

Kozlov: “How big of a fight is it going to be, and is it going to dominate the political landscape next year outside of the presidential election?”

McSweeney: “A hundred percent. This is the issue that matters.”

There is nothing illegal about such donations to get laws and issues passed. But political watchdogs say that type of big money from elected officials with deep pockets always raises concern about money’s impact on public policy.