DETROIT (Reuters) - Democratic front-runner Joe Biden was again the main target of his rivals at the second presidential debate on Wednesday, as many of the nine other candidates on stage took aim at his track record on race, criminal justice, immigration and healthcare.

Former Vice President Joe Biden watches as U.S. Senator Kamala Harris speaks on the second night of the second 2020 Democratic U.S. presidential debate in Detroit, Michigan, July 31, 2019. REUTERS/Lucas Jackson

“Go easy on me, kid,” the former vice president told Senator Kamala Harris of California with a smile as they greeted each other on stage before the debate began in Detroit.

But neither one had any plans to go easy, and they went after each other in a series of tough exchanges.

As the highest-profile candidates on the stage, both of them were also repeatedly targeted by the other candidates.

Biden did better than at the first round of debates in Miami last month, but his performance was still uneven. Harris was also on the defensive at times, failing to repeat her dominant performance in Miami.

Amid feisty exchanges, some candidates warned they should be focusing their fire on their real target: Republican President Donald Trump.

Here are some highlights from the debate.

MEDICARE FOR ALL

The first question went to Harris, who was asked to respond to the Biden campaign’s characterization of her recently released healthcare plan as a “have-it-every-which-way approach.”

“They are probably confused because they have never read it,” Harris responded.

She said her plan is a response to listening to voters, who want public and private options for now, with 10-year phase-in period to transition to a Medicare-for-all system, as opposed to a four-year phase-in period offered by progressive U.S. Senator Bernie Sanders of Vermont, who took part in Tuesday night’s debate.

Biden said Harris did not fully explain how she would pay for her plan. Harris countered that Biden’s plan would leave 10 million people uninsured and called it the “status quo.”

The question led to some of the most clearly articulated positions on expanding access to health insurance the candidates have offered to date.

Senator Kirsten Gillibrand of New York, another of the 10 candidates on stage, said Democrats need to remember that Republicans are chipping away at the Affordable Care Act enacted by former President Barack Obama and that Democratic candidates are at “risk of losing the forest for the trees.”

“This pitting against progressives, against moderates, saying one is realistic and the other doesn’t care enough - that to me is dividing or party and demoralizing us in the face of the real enemy here,” Senator Cory Booker of New Jersey said.

IMMIGRATION

After healthcare, the debate moderators moved on to immigration, asking Julian Castro, Obama’s former housing department head, why he broke with the administration’s former immigration chief to call for decriminalizing illegal border crossings.

“You’re not electing me to follow. You’re electing me to lead. And open borders is a right-wing talking point, and frankly I’m disappointed that some folks, including some folks on this stage, have taken the bait,” Castro responded.

The Texan was the first 2020 candidate to call for decriminalizing illegal crossings on the U.S.-Mexico border, and most of the others have followed. Of those onstage on Wednesday, congresswoman Tulsi Gabbard of Hawaii remains undecided on the issue, and Senator Michael Bennet of Colorado has rejected it outright.

“I have guts enough to say his plan doesn’t make sense,” Biden said of Castro.

New York City Mayor Bill de Blasio asked Biden whether he agreed with the deportation of 800,000 immigrants during the first two years of Obama’s administration - more than during the first two years that Trump was in the White House.

“To compare him to Donald Trump, I think is absolutely bizarre,” Biden countered.

Booker, again, told his colleagues they were “playing into Republican hands.”

CRIMINAL JUSTICE

The topic of criminal justice resulted in Biden and Booker engaging in one of the most fiery clashes of the night.

Booker signaled in the weeks leading up the debate that he was going to take Biden to task for his stewardship of a 1994 crime bill that exacerbated mass incarceration in communities of color.

Biden, who recently released a proposal that would undo major elements of the 1994 law, was prepared. He questioned Booker’s record as mayor of Newark, New Jersey, when the federal government investigated whether its “stop-and-frisk” policy targeted minorities.

Booker said it is “no secret that I inherited ... a police department with massive problems,” and sought to pressure Biden again on the 1994 law.

“This is one of those instances where the house was set on fire and you claimed responsibility for those laws. And you can’t just now come out with a plan to put out that fire,” Booker said.

On Booker’s criticism of Biden and the 1994 crime bill, Castro agreed: “He has flip-flopped on these things. And that’s clear.”

RACE

After a fiery exchange over race in the first debate, when Harris questioned Biden’s opposition to using mandatory busing to integrate schools in the 1970s, Biden’s campaign has said the two shared essentially the same stance on the issue. Moderators asked Harris on Wednesday whether that was accurate.

“That is simply false,” Harris replied, adding had she been in the Senate at that time she would have been “completely on the other side of the aisle” of the segregationist senators with whom Biden worked.

“And let’s be clear about this. Had those segregationists their way, I would not be a member of the United States Senate, Cory Booker would not be a member of the United States Senate, and Barack Obama would not have been in the position to nominate him to the title he now holds,” she said, referring to Biden.

Biden countered that when Harris was California’s attorney general from 2011 to 2017, San Francisco and Los Angeles remained among the most segregated school districts in the country and he “didn’t see a single, solitary time she brought a case against them to desegregate them.”

Other candidates jumped in after the exchange to criticize Harris’ civil rights record as California’s attorney general.

“She put over 1,500 people in jail for marijuana violations and then laughed about it when she was asked if she ever smoked marijuana,” congresswoman Gabbard said.

Harris recently came out to support fully legalizing marijuana and said she herself has smoked it, but her stance on the issue has evolved.