The second round of Democratic debates was completed on Wednesday night in Detroit, with 10 candidates onstage for the second of two back-to-back nights. The other 10 candidates who qualified for the debates appeared Tuesday on the same stage.

Our reporters followed all of the exchanges and fact-checked the candidates, providing context and explanation for the policy debates.

What the facts are

Joseph R. Biden Jr. defended himself against attacks on his support for criminal justice legislation that critics said resulted in racial disparities and mass incarceration.

What Mr. Biden said:

“Since 2007, I, for example, tried to get the crack powder cocaine disparity eliminated.”

This is misleading. It is true that in 2007 Mr. Biden called for reducing the longstanding disparity in which crack cocaine offenders — most of whom were black — received much harsher sentences than those arrested on charges of possession of powder cocaine. But what Mr. Biden failed to mention was that he was the architect of the disparity.

The disparity grew out of a 1986 law, the Anti-Drug Abuse Act, championed by Mr. Biden, that set a minimum of five years for 5 grams of crack or 500 grams of powder cocaine. It took more than 20 years for Mr. Biden to move to undo that provision; in 2007, Mr. Biden called the disparity “arbitrary, unnecessary and unjust” and acknowledged his own role in creating it.