Former vice president Joe Biden returned to a familiar refrain at the beginning of the third Democratic presidential debate: extolling Barack Obama’s record as president and his role in it. (You can watch Biden do this again and again in the video above.)

“I know that the senator says she’s for Bernie,” Biden said last week during the debate, referring to Sens. Elizabeth Warren (Mass.) and Bernie Sanders (Vt.), respectively. “Well, I’m for Barack. I think Obamacare worked.”

It has been a strategic move for Biden, who has made his campaign all about a binary choice between Trumpism and a return to the relative normalcy of the Obama years.

Even as Biden says his campaign is not a “continuation” of the Obama administration, he has invoked Obama and his record more than any candidate during the first three debates.

Biden has good reason to do this: Obama remains incredibly popular, especially among Democrats.

  • 60 percent of Americans approved of Obama’s job performance when he left office, according to a January 2017 Washington Post-ABC News poll.
  • Only 2 percent of Democrats rated Obama’s presidency as “poor,” according to a May 2019 CBS News/YouGov poll.
  • 44 percent of Americans said Obama was the best president of their lifetime, according to a June 2018 Pew Research Center survey.

Biden has tied himself to Obama in at least three campaign ads in 2019, a stark difference from when former vice presidents George H.W. Bush and Al Gore tried to distinguish themselves from their former bosses, as Politico’s Ryan Lizza noted last week.

When Democratic candidates have criticized Obama, and by extension Biden, they haven’t reaped any rewards. Biden’s national polling lead has remained steady, according to the RealClearPolitics average, while no candidate who criticized Obama during the first two debates sustained a polling bump.

By the third debate, Democrats had apparently learned their lesson.

Of 16 non-Biden references by candidates to Obama during last week’s debate, 13 were positive references to the 44th president.

Emily Guskin contributed to this analysis.