The biggest loser in last night’s Democratic presidential primary debate was not on the stage. It was former president Barack Obama. Throughout the night, as rivals challenged Joe Biden, Obama’s vice president and current frontrunner, it took the form of blistering attacks on the Obama administration over immigration, criminal justice, and even his signature achievement, the Affordable Care Act.

Part of this is simply the inevitable consequence of Biden, with a big lead in the polls, being everyone’s most natural target. While it’s true he has decades of political life to take aim at, his last significant political position was serving as Obama’s number two for eight years. Conceding that he and his boss did a bang-up job in the White House goes a long way towards conceding this current race to him. But last night we saw that won’t happen without a fight.

The issue is actually far deeper than electoral calculations. In the just more than a decade since Obama first sat in the Oval Office, the Democratic Party has careened to the left like a sports car with a blown tire making a pass on the Autobahn. Last night’s debates saw defenses of socialism, calls to essentially open the borders, free money for everyone, and plans for government-controlled health care with a price tag longer than a CVS receipt.

On immigration, Biden was slammed by both Cory Booker and Bill de Blasio over Obama’s extremely high number of deportations and Biden’s argument that the United States should be selective about who it lets into the country. Biden struggled to defend the so called “deporter in chief,” arguing basically that Obama made a good start with the now defunct DREAM Act allowing younger people brought here illegally a path to citizenship, but beyond that was stymied by GOP control of the House.

On criminal justice reform, it was also Booker trying to take aim at the former vice president, who argued that since 2007, which includes his entire term as vice president, he had work to eliminate discrepancies in sentencing for crack and powder cocaine, among other things.

Booker said Biden was “dipping into the Kool-Aid and, you don’t even know the flavor,” which is apparently a saying in Newark, New Jersey. It’s not entirely clear what it means, but it clearly wasn’t a compliment. Booker also said the current criminal justice system is broken, a subtle swipe at the Obama administration for not having done more to fix it.

By far the most damning attacks on Obama’s, and by extension, Biden’s, stint in the White House came over health care. The Affordable Care Act, which Biden once famously called a “big f—ing deal,” was basically savaged by almost every candidate. This was the signature achievement of the Obama administration and most candidates essential want to scrap it in favor of a so-called Medicare for All plan. Here again, Biden proceeded carefully, admitting that tweaks were needed, but he stood by the ACA’s essential framework.

There is some mostly wrong conventional wisdom that Obama exercised the office of president like he was a moderate Republican. This goes way too far. On judicial appointments, the economy, and foreign policy, to name a few, Obama governed as a liberal Democrat. But there is no question that what it means to be a liberal Democrat has changed wildly since Obama left office.

Today’s major force in the Democratic Party is led by the “Squad,” a cadre of socialists connected with the Justice Democrats PAC. So soundly has the Squad reset the agenda of the party that, with the possible exception of gay marriage, now a constitutional right, there is little if any of Obama’s agenda to praise if you are on the left.

All in all, Biden had a pretty good night. He was the focus of attention and seemed energetic in parrying the attacks coming at him from around the stage. Some of that old Uncle Joe charm came across. Biden basically succeeded in walking a tightrope by saying Obama had done very well, but there is still much to do.

Obama did not fare nearly as well. In large part, of course, that was because he wasn’t there to defend himself, and political reality meant Biden couldn’t full-throatedly either. At one point Julian Castro did praise Obama’s handling of the economy, thanking him to huge applause from the crowd.

When we look at the last three Democrats to be president over the last few decades, Jimmy Carter is viewed as a nice guy whose one term was ineffective. Bill Clinton is almost a persona non grata on the left, not only for sexual misconduct but also for criminal justice and welfare reform. Is it now time for Democrats to throw Obama under the bus? Judging from last night, it certainly looks that way.