Democrats vying for the 2020 presidential nomination are apologizing for their past apostasies in a manner that would make Marty Funkhouser proud.

Former Vice President Joe Biden, who has been mulling a run for months, expressed regret for the "big mistake" of supporting tougher sentences for drug possession in the 1980s and 1990s. Biden even attacked then-President George H. W. Bush in 1989 for being too soft on crime and drugs.

"It was a big mistake when it was made. We thought, we were told by the experts, that crack—you never go back. It was somehow fundamentally different. It’s not different," he said at the National Action Network this week. "But it’s trapped an entire generation."

One recently declared candidate, Sen. Kirsten Gillibrand (D., N.Y.), has described herself as "callous" in her former immigration views and said she "couldn't have been more wrong" about her previous support for gun rights—she once sported an "A" rating from the National Rifle Association but now proudly has an "F."

As MSNBC host Rachel Maddow put it, Gillibrand has "been on her own party's right. She has been on her own party's left."

Another declared candidate, Rep. Tulsi Gabbard (D., Hawaii), released a full apology video for her previous anti-LGBT views.

"In my past, I said and believed things that were wrong," she said. "And worse, they were very hurtful to people in the LGBTQ community and to their loved ones. I’m deeply sorry for having said them. My views have changed significantly since then, and my record in Congress over the last six years reflects what is in my heart."

Although she has shifted completely to being a strong supporter of gay rights, her contrition may not be enough for the party. Left-wing comedian Samantha Bee, during a segment on women running for president on Wednesday, dismissed Gabbard as a viable candidate.

Sen. Bernie Sanders (I., Vt.) was forced to apologize to women who alleged sexual harassment and pay disparities on his 2016 campaign, initially saying he was a "little bit busy" running around the country to be aware of the situation at the time.

Some of the apologies have been more passive by possible and declared candidates.

Sen. Kamala Harris (D., Calif.) said she took full responsibility for her past decisions that upset progressives as a prosecutor, Sen. Elizabeth Warren (D., Mass.) acknowledged she was not a "person of color" while defending her decision to release a DNA test revealing scant Native American ancestry, and former New York City Mayor Michael Bloomberg, who's never backed off his support for the "stop-and-frisk" program, acknowledged not all of his decisions in office were "perfect."

Biden also quipped he was sorry for the sin of liking Republicans during a speech to the U.S. Conference of Mayors on Thursday. Given how the primary is shaping up, it might not have been a joke.