In the second night of the July 30-31 Democratic presidential debates held in Detroit, CNN's moderators zeroed in on the candidates' differences on health care, criminal justice, race, and immigration, setting up clashes on the stage with 10 candidates. Former Vice President Joe Biden, leading in national polls, faced the lion's share of attacks from his challengers. Sen. Kamala Harris (D-Calif.) also faced many attacks from Biden and other candidates on her Medicare-for-All plan and record as attorney general of California.
1. Health Care
CNN's moderators started off the night with a series of questions about Sen. Harris' Medicare-for-All plan, released on July 30. Harris' plan envisions expanding the existing government-run health insurance plan for seniors to all Americans, but allowing individuals to buy private insurance plans, as current Medicare does. She also envisions a 10-year phase-in, keeping the existing health-insurance system in place as the new Medicare system kicks in.
Former Vice President Joe Biden attacked it, accusing her of "double talk." He argued for a so-called public option, allowing individuals to buy a government-run insurance option on the existing Obamacare exchanges. Sen. Michael Bennet (D-Colo.) joined Biden in attacking Harris' plan and advocating for a public option.
However, Sen. Cory Booker (D-N.J.) zoomed out of this nuanced health care debate by pointing out that the existing health care law passed by President Barack Obama was at risk by a lawsuit making its way to the Supreme Court that could potentially invalidate it. Not on the stage was Sen. Bernie Sanders, who has favored a more radical version of Harris' plan, without the private insurance Medicare component.
Next up was a clash over immigration. Former Housing and Urban Development Secretary Julian Castro and Biden debated whether crossing the border should be a criminal or civil offense. Under a 1929 U.S. immigration law, it is a criminal offense, giving the Trump Administration the legal backing to enforce a "zero tolerance" policy. Biden argued that it was a criminal offense, while Castro said it should be a civil offense.
"It's a crime. It's a crime," said Biden.
"First of all, Mr. Vice President, it looks like one of us has learned the lessons of the past, and one of us hasn't," said Castro to applause.
Biden took further hits from New York City Mayor Bill de Blasio and Booker over former President Obama's immigration record. De Blasio challenged Biden to defend the Obama Administration's record of deporting some 3 million people. Biden evaded the question, and Booker called him on it: "You can't have it both ways. You invoke President Obama more than anybody in this campaign. You can't do it when it's convenient, and then dodge it when it's not."
3. Criminal Justice
Booker and Biden next tangled over criminal justice reform. Booker hit Biden over his support for the 1994 crime bill that Biden has taken credit for passing when he was a Delaware senator, but has since been blamed for an explosion in mass incarceration. Booker claimed that Biden could not be a credible mantle for reform, as having touted his backing of it.
Biden pointed out that the bills had been passed years ago and "overwhelmingly," which is true. But he then pivoted to a seemingly well-rehearsed attack criticizing Booker's record on criminal justice as mayor of Newark. "There was nothing done," said Biden.
"There's a saying in my community: if you're dipping into the Kool-Aid, you don't even know the flavor," quipped Booker.
4. Race and Busing
Biden and Harris clashed again over race and busing, as they had in the first debate. Harris denied that the two candidates had the same position on busing, saying that it was "simply false." Harris reiterated her attacks on Biden for working amicably with segregationist senators in the 1970s.
Biden, as he did with Booker's record in Newark, pivoted to Harris' past job as Attorney General of California. "I didn’t see a single solitary time she brought a case against them to desegregate,” he said of school districts in Los Angeles and San Francisco. "This is simply not true," responded Harris.
Rep. Tulsi Gabbard (D-Hawaii) also took aim at Harris' record as a prosecutor and attorney general. Harris, again, offered a general defense of her record and said that she was "proud" of her work.
5. Climate Change
Washington Gov. Jay Inslee slammed Biden over climate change, though Biden seemed to ultimately agree with him. Biden was asked whether there would be any role for fossil fuels under his climate change plan. "No, we would work it out, we would make sure it's eliminated," he said of subsidies.
"We cannot work this out," said Inslee, "The time is up. Our house is on fire." Biden then chimed in that he was for Inslee's plan. Harris also said she agreed with Inslee.
6. Women's Rights
Biden seemed to fare better after an attack from Sen. Kirsten Gillibrand (D-N.Y.) over a 1981 op-ed that he wrote and she read at the debate that argued that expanded child tax credits would enable “the deterioration of the family.”
Biden pivoted back to her past support of his record on equal rights and said, “I don’t know what's happened, except you’re now running for President."
More must-read stories from Fortune:
—In a debate over differences, these are the topics not discussed on night one
—Democrats spar over health care, race, and gun violence in high-energy debate
—4 things we learned from night one of the second Democratic debate
—Highlights from the first night of the second Democratic debate
—Detroit happily steps into role of political HQ as Democrats gather for debate
—Abortion, reparations, Israel: Topics to watch during second Democratic debate