A strategist who helped Rep. Alexandria Ocasio-Cortez (D-N.Y.) win a seat in Congress was fired for a “divisive” tweet he wrote about her fellow Democrats, the New York congresswoman revealed.

Saikat Chakrabarti, chief of staff for Ocasio-Cortez, abruptly resigned on Aug. 2, with media reports citing a series of controversies. Corbin Trent, director of communications for the congresswoman, explained at that time that Chakrabarti decided to move to work with her New Consensus to further develop plans for a Green New Deal.

But in an interview with the New York Daily News posted Thursday, Ocasio-Cortez rebuked her ex-chief of staff for comparing some of her centrist colleagues to racist Dixiecrats, calling his comments “divisive”.

Ocasio-Cortez said her strategist’s resignation had nothing to do with his June 27 tweet comparing members of the moderate Blue Dog Coalition to “Southern Democrats” in the early 20th century who opposed desegregation efforts.

“I think it was divisive. I believe in criticizing stances, but I don’t believe in specifically targeting members,” she said.

In a tweet in June, Chakrabarti attacked Rep. Sharice Davids (D-Kansas), one of the first Native American women to enter Congress, accusing her of enabling “a racist system” after she voted in favor of a Senate border bill not backed by progressives. A month later, he cast centrist Democrats as the “new Southern Democrats.”

Chakrabarti’s comments infuriated moderate Democrats and ignited uproar inside the House Democratic Caucus during policy spats between progressive members and party leadership.

In the interview, Ocasio-Cortez said there was an “internal conversation” in her office after the tweet and they had corrected it. She said Chakrabarti “immediately took the tweet down.”

Controversial tweet is not the only issue Ocasio-Cortez’s former chief of staff is facing. Federal government agencies are investigating alleged campaign finance misconduct involving Chakrabarti, according to the New York Post.

The probe focuses on two political action committees PACs—Brand New Congress and Justice Democrats—founded by Saikat Chakrabarti to rally behind liberal candidates in elections, which recruited Ocasio-Cortez and helped her become congresswoman.

Ocasio-Cortez dismissed the complaint, saying it was a form of legal trolling and filed by Republican groups.