Ex-Goldman Sachs Chief Executive Lloyd Blankfein escalated a Twitter beef against fellow ex-Brooklynite Sen. Bernie Sanders on Thursday, after the Democratic hopeful put the billionaire on a list of “modern-day oligarchs” opposing his candidacy.

“Don’t know why Sen. Sanders picks on a retiree like me. I think he’s always looked down on me because he grew up in a fancier neighborhood in Brooklyn,” Blankfein wrote in a tweet

While Blankfein was born in the Bronx, he grew up in the Linden housing projects in East New York. Sanders, a political independent who identifies as a Democratic Socialist, grew up in the middle-class neighborhood of Midwood.

On Thursday, Sanders’ campaign included a quote from Blankfein calling his candidacy a “dangerous moment” in a list of “anti-endorsements” from other powerful US businessmen that also included JPMorgan CEO Jamie Dimon and Disney CEO Bob Iger.

Sanders’ campaign didn’t return a request to respond.

This isn’t the first time the billionaire banker, who left the bank last year, has singled out Sanders. In February, Blankfein took issue with the senator calling him out over stock buybacks, which he claimed enrich investors at employees’ expense.