Joe Biden faced repeated challenges from other 2020 Democratic presidential candidates during Wednesday night’s debate in Detroit.

The former vice president sparred on issues like criminal justice reform and immigration with fellow contenders like Sen. Cory Booker (D-New Jersey) and former Housing and Urban Development Secretary Julian Castro. Booker hammered Biden for his support for a 1990s crime bill that led to mass incarceration of black Americans. Biden then in turned criticized Booker for his policing record during his tenure as tenure as mayor of Newark, New Jersey.

Many of the central points of the debate appeared to concern whether or not the Democratic Party should let go of its views on major issues that were common during Biden’s time as a senator and Vice President. At several points, Biden cited the fact that Barack Obama chose him as his running mate in 2008 to defend his record on multiple issues like race relations.

Sen. Kirsten Gillibrand (D-New York), for instance, called out Biden for his vote opposing a chid care credit during the 1980s and over an op-ed he once wrote about working mothers in the United States.

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Biden and Sen. Kamala Harris (D-California) also had a tense exchange while discussing their respective plans to change the national medical care system. Harris was touting her support for a less extreme version of “Medicare for All,” while Biden countered by saying he believed this type of system would lead to many people losing private health insurance.

Castro blasted Biden and Obama for deporting hundreds of thousands of undocumented immigrants during their time in the White House, and reiterated his plan to decriminalize illegal migration through the southern border by making it a civil violation rather than a felony.

“The secretary, we sat together in many meetings. I never heard him talk about any of this when he was the secretary,” Biden said of Castro.

Two polls released earlier this week showed Biden still holding a significant lead over other top 2020 Democratic opponents like Sens. Bernie Sanders (I-Vermont) and Elizabeth Warren (D-Massachusetts).