Hi, and welcome to a special post-debate edition of On Politics. I’m Lisa Lerer, your host.

Where did our love go? All you need is love. It must have been love … but it’s over now.

Senator Cory Booker entered the 2020 race preaching the gospel of “radical love.”

He talked about restoring “grace and decency” and erasing “the lines that people think divide us — racial lines, religious lines, geographic lines.” It was a theme rooted in the political legacy of President Barack Obama, who rode a message of national unity to become the first black man to win the White House.

Well, the love is gone.

In the second debate, Mr. Booker slammed Joe Biden on civil rights, immigration and the former vice president’s record on criminal justice reform.

He chided Mr. Biden for interrupting him: “I didn’t interrupt you. Please show me that respect, sir.”