DETROIT, Mich. (CBSNewYork) – It was a rock’em, sock’em debate that surprisingly started with front-runner Joe Biden begging for mercy.

“Go easy on me kid,” the former vice president said.

California Sen. Kamala Harris, who some thought embarrassed Biden at the first debate, certainly had the knives out again. But before Harris and Biden could engage, 2020 longshot Bill de Blasio got in the first licks.

“Joe Biden told wealthy donors that nothing would change if he were president. Kamala Harris said she’s not trying to restructure society. Well I am,” de Blasio declared.

“When I’m president we will tax the hell out of the wealthy.”

That’s when the mayor of New York’s critics chimed in – and they weren’t on the stage.

“Fire Pantaleo, fire Pantaleo!”

Protestors interrupted de Blasio, demanding he fire NYPD Officer Daniel Pantaleo for the Eric Gardner chokehold case.

The rowdy crowd also interrupted Cory Booker who had to pause his comments to let them finish.

The Garner case became a huge flashpoint, with candidates roasting de Blasio.

“11 different times Eric Garner said he couldn’t breath,” Julian Castro said.

“He was killing Eric Garner and yet he has not been brought to justice. That police officer should be off the street.”

“That person should be fired and if I were the mayor I would fire him,” Sen. Kirsten Gillibrand added.

The mayor tried to turn the tables blaming the Obama-Biden administration for not brining a civil rights case against the officer.

“Mr. Vice President tell us what did you do to try and spur on the Justice Department to act,” the mayor asked.

“The fact is we’re talking about things that happened a long time ago and now all of a sudden I got to find it fascinating everybody’s talking about how terrible I am on these issues. Barack Obama knew exactly who I was and he chose me and said it was the best decision he ever made,” Biden stated.

On many of the issues, health care, criminal justice environment, the candidates tried to gang up on front runner Biden – to tarnish him.

“I asked the vice president point blank did he use his power to stop the deportations, he went right around the question,” de Blasio added.

“I guarantee you if you’re debating Donald Trump he’s not going to let you off the hook so did you say the deportations were a good idea or did you say it was a mistake we should do it which one?”

“I was vice president. I keep my recommendations private unlike you,” Biden fired back at the mayor.

The vice president also took it on the chin from the Trump family, with Donald Jr. tweeting: “I think we all see why Obama hasn’t endorsed his VP of eight years?”

He added in another tweet “even de Blasio destroys Joe Biden!”