Former Barack Obama adviser David Axelrod offered Vice President Kamala Harris what he believes will be the key to defeating former President Donald Trump in their upcoming Sept. 10 presidential debate on ABC News.

Harris’ “best” strategy would be to “jiu jitsu” Trump, Axelrod told CNN’s Erin Burnett on Tuesday’s broadcast of her “OutFront” show.

“Use his negative energy against him,” Axelrod suggested would be the best way for Democratic candidate Harris to attack her Republican rival.

“I think a majority of Americans don’t want to vote for Donald Trump. He’s not particularly popular. A lot of it has to do with his behavior,” Axelrod continued in a video that Raw Story shared online.

“So, I would let him act out,” he added. “And I would just talk to the country. And I’d have some humorous jabs ready to go and asides ready to go but I’d primarily talk to the country who wants to hear about Kamala Harris and where she leads because they’re looking for an alternative to Donald Trump.”