J.B. Pritzker was Hillary Clinton’s top fundraiser — kicking in millions from his own deep pockets — and as the billionaire venture capitalist launched his own Democratic gubernatorial campaign on Thursday, he sought to cast the race as an aftershock of the earth-shaking presidential contest.

“You want to know why I’m running for governor? Because everything we care about is under siege by Donald Trump and Bruce Rauner,” Pritzker said.

“Gov. Bruce Rauner is a failure. He promised a ‘Turnaround,’ and all we got was the runaround. He said he would stand up to the special interests and instead he’s become his own special interest,” Pritzker said. “He said he wanted to shake up Springfield but instead he’s tearing it down.”

Pritzker portrayed Rauner as in league with the Republican president, but he also said the governor was afraid to stand up to Trump.

The Democrat took to the podium at the Grand Crossing Gym, 7655 S. Ingleside Ave., to Florence and the Machine’s “Dog Days Are Over” and spoke for about 15 minutes.

“Let me take this opportunity to introduce myself,” Pritzker said. “My name is J.B. Pritzker, and I’m running for governor of Illinois.”

Pritzker touted his work at 1871, the innovation hub that he said has created 6,000 jobs. He also spoke about his work with early education for at-risk children, his push to get Holocaust education into schools; and his endowment in the Center on Wrongful Convictions.

“My mother raised me with an abiding sense of social justice, and my father taught us to think big,” Pritzker said. “So their progressive values and those of my faith have led me to do big things that have a lasting impact on peoples’ lives.”

Pritzker also extolled his fundraising efforts and support for Hillary Clinton, while vowing to fight against Trump “as a private citizen and as your governor.”

“These terrible policies are magnified by his local partner, Bruce Rauner, who is just too afraid to stand up to Donald Trump. Illinois needs a progressive governor with a proven record of getting results, balancing a budget, creating jobs, raising wages, preserving and expanding health care for all, and bringing economic justice to the people of Illinois.”

He cited the state’s last place finish in education funding and its surging violence as evidence of the “very fibers of our state breaking down.”

Even the location of the event was chosen with an eye toward the presidential race.

The gym is in the 8th Ward, where Clinton won nearly 67 percent of the vote to 32 percent for Bernie Sanders in last year’s primary election. In November, the South Side ward voted overwhelmingly for Clinton with 97 percent to Trump’s 1.5 percent.

The ward’s alderman, Michelle Harris, attended Pritzker’s rally, along with fellow City Council members Pat Dowell (3rd), George Cardenas (12th) and Walter Burnett (27th).

Choosing the predominantly African-American ward was also a nod to black voters, a crucial demographic for Democrats. So far, no black — or Hispanic — candidates have officially entered the race for governor, although Chicago Treasurer Kurt Summers is mulling a run.

While Pritzker worked to link Rauner to Trump, the governor’s Republican Party has been portraying Pritzker as a disciple of state House Speaker Mike Madigan. On Thursday, the GOP amped its attacks on Pritzker, releasing audio of Pritzker telling “party insiders” that if the state put the income tax rate back at 5 percent, it could provide a “good way … toward getting real revenue in the state.”

Asked by reporters whether he’d support a tax hike, Pritzker instead said he wants a tax on the rich.

Josephine “Mother” Wade talks with JB Pritzker after he announced his run for Illinois Governor at Grand Crossing Gym on April 6, 2017. | Max Herman/For the Sun-Times

“I think that we ought to start with the millionaires and billionaires and make sure that they’re paying taxes first, and then you know we’re not going to talk about raising taxes on middle class families until we take care of hat problem,” Pritzker said.

Pritzker said the campaign is “all about beating Bruce Rauner” — while urging all Democratic candidates to unite against the Republican governor.

“The Republicans are trying to take over this state and they have this right wing Koch brother agenda that they’re pushing. We got to fight that and all of us should train all of our fire power, everybody that’s running in the Democratic primary, on Bruce Rauner because he’s failed this state. Two plus years without a budget. We’ve got to fix the problems of the state, and it’s going to take a Democrat to do that. I’m the right guy.”

The state Republican Party also released a digital ad, seeking to tie Madigan to Pritzker. Rauner for months has said Madigan is holding up the budget to force a tax hike. The party called the tax hike “the Madigan-Pritzker plan.”

Pritzker’s entrance into the race was expected. He formed an exploratory committee last month to test the waters and raise money for a run — and immediately kicked in $200,000 from his own pocket.

Sun-Times columnist Michael Sneed broke the news of his announcement early Thursday.

With a net worth Forbes estimates at $3.4 billion, Pritzker — like Rauner and Democratic rival Chris Kennedy — is able to self finance his campaign. Kennedy has already put $250,100 of his own money into the race, but he said Thursday that he raised an additional $750,000 from others.

Pritzker is a successful entrepreneur and investor. His father co-founded Hyatt hotels, a prime source of the family’s wealth.

Pritzker ran unsuccessfully for Congress in 1998, comng in third place in a three-way primary won by Jan Schakowsky. In 2008, he served as Clinton’s national campaign co-chair in her bid for president, and contributed $14 million to her campaign and related Democratic organizations last year.

Besides Kennedy, announced candidates in the race include Ald. Ameya Pawar (47th); state Sen. Daniel Biss; Bob Daiber, a superintendent of schools in Madison County, and business owner Alex Paterakis.