Billionaire J.B. Pritzker is taking heat from his primary opponents for comments he made about President Barack Obama in March of 2012.

A Bloomberg TV host asked Pritzker, who had previously supported Hillary Clinton’s primary bid in 2008, “Are you going to vote for the President?” Pritzker replied, “We’ll have to wait and see. I don’t know who the nominee is going to be on the Republican side.”

The Republican candidates running in that race were Mitt Romney, Rick Santorum, Ron Paul and Newt Gingrich.

We tried to ask Pritzker which one of those Republican candidates he might have had his eye on, but his campaign team whisked him away before he could answer. A staffer claimed he was on a tight schedule to return to Chicago. Later, the campaign provided us with audio remarks Pritzker made in Chicago on Wednesday.

“I’ve done everything that I can to support Democratic candidates,” Pritzker said. “I’m a Democrat through and through.”

“I supported Barack Obama in 2012. I supported Barack Obama in 2008 at the end of the primaries,” he explained.

Pritzker initially supported Hillary Clinton over Obama in 2008, and remained close to the Clinton family as a donor and informal campaign advisor during her 2016 run. The relationship between Clinton and Obama was often fractious. Primary campaign tensions lingered on and strained that relationship even during her term as Secretary of State.

Pritzker’s sister, Penny Pritzker, served as President Obama’s Commerce Secretary and co-chair of his 2012 re-election campaign. She helped to bundle campaign donations for Obama, raking in a total of $874.6 million dollars, the highest earning political campaign in American history.

Open Secrets lists J.B. and his wife Mary K. Pritzker as the 12th top ranked political donors to outside spending groups in the nation, 39 spots higher than billionaire conservative Charles Koch.

The Pritzker family ranked even higher in overall political donations to federal candidates and political action committees with a grand total of $22,189,052. Every penny went to Democratic candidates or groups. If Pritzker actually had been considering backing a Republican in the 2012 general election, it would have likely been the first time.

Undoubtedly, Republican politicians have groveled for a share of Pritzker’s wealth. In a donor category labeled “Hard Money,” Pritzker was second only to Sheldon Adelson, placing him as one of the premier political king makers in the country.

The Pritzker siblings may have split over Obama and Clinton in Democratic primary races, but their recent political bets have all been placed on Democrats.

The lengthy list of donations reveals Pritzker has in fact put his money where his mouth is. However, the size of those donations may not play well in a Democratic primary. A 2015 Bloomberg Politics poll found 78% of the country thought the Citizens United ruling should be overturned, a landmark Supreme Court decision which has been widely criticized for inviting unlimited amounts of dark money into political campaigns.

Senator Daniel Biss, a Democrat from Evanston, has repeatedly criticized “billionaires who try to buy elections.” He recently mocked Pritzker for a $5 million donation to his own campaign by tweeting a picture of a $25 check written to himself. Thursday afternoon, Biss again seized the chance to claim the progressive high ground in this race for governor, launching an attack at Pritzker’s political makeup.

“He’s presenting himself now as a progressive Democrat,” Biss said. “I’ve never known him to be that in the past. His track record in the past doesn’t show how that would be the case. I think we need to hear from him what he was hoping to support.”

Biss again mocked Pritzker as a moderate pretending to be a progressive.

“Maybe he was hoping a Republican candidate running against President Obama in 2012 would be more progressive than President Obama,” he said dryly. “That’s not what I saw coming out of the Republican primary in 2012 and I’d be really curious to hear a detailed explanation from Mr. Pritzker.”

“I just want J.B. Pritzker to explain who he is. Let us know the story of J.B. Pritzker and all those pieces of history of not being sure if he wanted Barack Obama to be reelected president in 2012 to the support for a series of moderate candidates over the years. That’s nothing to be embarrassed about. He just needs to tell us and give a clear picture and not just try to become somebody else.”

A campaign spokesperson for Chris Kennedy said, “We’ll let the video speak for itself. The voters can be the judge.”

A staffer also pointed out that Kennedy supported state senator Barack Obama when he ran for the U.S. Senate back in 2004.

The former president has not yet endorsed a Democrat in this primary race. In his first public remarks since leaving the Oval Office, Obama warned college students about the dangers of undue influence on public officials. He told an audience at the University of Chicago, “It’s harder and harder to find common ground because of the money in politics.”