A new lightning bolt erupted Wednesday from the dark cloud that surrounds the looming teachers strike when Chicago Teachers Union President Karen Lewis called Gov. Bruce Rauner a “new ISIS recruit.”

“Has Homeland Security checked this man out yet? Because the things he’s doing look like acts of terror on poor and working class people,” she said, citing Rauner’s decision to slash millions in state funding to CPS and numerous social service groups.

“He talks about me all the time, so guess what, gloves are off,” Lewis told reporters after speaking at a luncheon hosted by the City Club of Chicago, a non-partisan group that hosts forums and debates.

She said that Rauner’s use of the state budget impasse — and its negative impact on social services and education — as leverage to achieve union-weakening reforms equates to terrorism.

A Rauner spokesperson shot back at Lewis and the ISIS comparison.

“This kind of rhetoric has no place in American public discourse and sets a terrible example for our kids,” Rauner spokesperson Catherine Kelly wrote in an emailed statement.

In her speech, Lewis noted that despite Rauner attacking CPS, he had no problem using his influence to get his daughter into one of the system’s best schools, Walter Payton High School, instead of having her attend New Trier, the public school in Winnetka, where Rauner has a home.

“With nine houses, who knows where he and his children actually lived when he clouted his daughter in that school,” Lewis said.

The heated remarks come as CPS and CTU are in the midst of negotiating a new teachers contract. The teachers union recently rejected an independent, third-party arbitrators report on a proposed contract that mirrored an earlier offer that CTU’s leadership also rejected.

With that rejection, the teachers union could strike as early as the middle of next month.

Lewis said the rejection of the report was not an in-your-face maneuver and said teachers are not “petulant little children.”

“We can’t just sit down and shut up . . . If you don’t stand up, these rich people will mow you down,” she said.

Asked if the deal, which Lewis initially characterized as a “serious offer” before reversing course, would have a shot of passing if offered up to CTU’s rank-and-file in a referendum vote, she said: “I don’t know. I doubt it. That’s not what we’re hearing.”

Lewis also noted that House Speaker Michael Madigan should not be compared with Rauner.

“People need to know who is the bad guy and bully in this, because a lot of people don’t realize it. You know, a lot of people are sitting back thinking ‘Oh. It’s both of them . . . it’s Madigan and Rauner, they’re the same.’ They’re not the same.”

Madigan, she said, is “somebody who’s trying to get things done.”

There’s no chance, Lewis said, that her extreme rhetoric will boomerang on her.

“(Rauner is) not at the (negotiating) table with us,” she said.

Lewis shrugged off a comment from a reporter who pointed out that Rauner would ultimately have to sign off on any future state funding for CPS.

Lewis said an offer announced Wednesday by Chicago Public Schools CEO Forrest Claypool to enter into binding arbitration with CPS was a publicity stunt to insert himself into the day’s event.

“Like I said, he has my phone number, he could have called me and said we’d like to try this,” she said. “So this is a pure publicity stunt.”

During her speech, Lewis ticked off a series of reasons why she feels CPS is untrustworthy, ending with, “Need I remind you of the SUPES scandal,” referring to the contracting scandal that resulted in the resignation and indictment of ex-CPS CEO Barbara Byrd-Bennett.