Rep. Alexandria Ocasio-Cortez's communications director Corbin Trent has left her reelection campaign and has joined Sen. Bernie Sanders's presidential election campaign.

The unexpected departure was discovered by the New York Post on Thursday after a reporter had emailed him asking for comment. Trent refused to say why he departed the New York Democrat's campaign.

Trent was formerly Ocasio-Cortez's communications director in her D.C. office but was reassigned to her reelection campaign in August.

The 31-year-old was a co-founder of Justice Democrats, which helped his former boss to win her congressional seat and become the youngest woman elected to the House.

Trent said he is now with Sanders's 2020 presidential campaign, where he will work on communications and strategy. Ocasio-Cortez endorsed the Vermont independent in October.