Hundreds of lefty demonstrators marched through downtown Madison, Wisconsin, spewing anti-cop venom, stopping traffic and harassing diners as they protested the killing of Corey Ruiz, a career criminal who allegedly stabbed a police officer with a knife before being shot.

Nearly 500 people marched from the intersection of Williamson Street and South Baldwin Street — where the 38-year-old was shot three times on Wednesday during a struggle with several police officers — to the Madison Police Department headquarters on Friday.

Video showed some demonstrators stopping traffic and confronting at a female motorist who insisted she was an “ally” during a streetside struggle session.

Hundreds of angry protestors gathered at the Police Department headquarters in downtown Madison, Wisc., on Friday. James Keivom for NY Post

“You’re going to sit there and watch it all go by and you’re going to think about it, c–t!” one yelled at the helpless driver.  

“I am 100 percent an ally of the community,” she pleaded with the protestors who surrounded her car. 

“I have lived in this neighborhood for 27 years. F–k the cops. I wanted to join the protest!” she said. “This guy calling me a c–t doesn’t help anyone’s cause.”

She added: “I’m an ally. I wanted to join the protest. I want to be part of this.”

Other protesters who held a Black Lives Matter flag harassed diners sitting outside at an upscale restaurant.

One local resident was accosted by protesters but insisted she was an “ally” who wanted to join the march. Steven Vago

“It’s your world. You’re part of the system whether you want to admit it or not,” the demonstrator said through a megaphone 

“White silence is violence!” protesters chanted at others sitting outside enjoying their dinner. 

A few hours later, a pair of protesters hit a car window when the driver refused to stop for their procession.

The Party for Socialism and Liberation held signs reading “jail killer cop. Justice for Corey Ruiz.”

Angry protesters hijacked the podium during a police press conference on Thursday — pushing aside Madison Police Chief John Patterson during an update on the shooting.

One woman held up a sign that read: “Corrupt cops deserve to die too!!

Corey Ruiz, a homeless man with a lengthy criminal record, was shot to death
on Wednesday during a struggle with police officers. Wisconsin Department of Corrections

“You’re gonna say the same thing you all say every time a black body gets shot down in this city!” the man, who identified himself as Carlos Jackson, shouted. Jackson then launched into a tirade about corruption, revolution and “Zionists.”

Ruiz was a homeless ex-con with a history of drug abuse and a lengthy criminal record, including for assaulting cops, according to court records and friends who spoke to the Wisconsin State Journal.

He was allegedly canvassing the area armed with a fixed-blade knife at the time of his confrontation with police, which led to one officer suffering a knife wound.

Ruiz was being held and struggling with several police officers when one fired three shots at point blank range, according to a viral video.