How Alexandria Ocasio-Cortez Learned to Play by Washington’s Rules

“They are frankly much closer in that dynamic and much closer in overlapping than a lot of people tend to realize,” she said.

Ms. Ocasio-Cortez has cut back on her appearances on behalf of Justice Democrats and has begun bolstering her fellow incumbent freshmen lawmakers, like Representative Joe Neguse of Colorado, a member of Democratic leadership whom she will support at a fund-raiser in Boulder this week. In April, she rallied around some of her colleagues who flipped districts President Trump won in 2016, encouraging her Twitter followers to donate to their campaigns. She diligently reached out to the so-called majority-makers on her committees — the centrist freshmen who flipped Republican-leaning seats — to win them over.

Her aides, however, continued to carry the Justice Democrats flag without restraint, tweeting out their support when the group challenged incumbents, to the dismay of Democratic aides and lawmakers. A flash point came in July when Saikat Chakrabarti, then her chief of staff, ignited a firestorm by accusing centrist Democrats of enabling “a racist system” after they blocked an effort to defund immigration enforcement as part of an emergency border aid package. In a post on Twitter, he compared them to “new Southern Democrats,” a reference to segregationists. It was a remarkable breach of protocol for an unelected aide.

Mr. Jeffries used the House Democrats’ official Twitter account to deliver a biting warning shot in a now-deleted tweet that singled out the chief of staff. Two weeks later, Mr. Chakrabarti announced he would leave the office entirely. Ms. Ocasio-Cortez’s new chief, Ariel Eckblad, a former aide to Senator Kamala Harris of California, is well-versed in the workings of Capitol Hill and is widely seen as a sober-minded replacement. Corbin Trent, who had been handling communications for both Ms. Ocasio-Cortez’s campaign and her congressional office, a highly unusual arrangement, has returned to the political side.

The rift was an escalation of a feud that began days earlier when Maureen Dowd, The New York Times columnist, asked Ms. Pelosi about the fury from the Bronx Democrat and three other progressive freshmen over the border aid package. The speaker noted that the group had failed to persuade any other Democrats to join them in voting against the House’s version of the bill.

“All these people have their public whatever and their Twitter world,” Ms. Pelosi said then. “But they didn’t have any following. They’re four people, and that’s how many votes they got.”