Representative Tulsi Gabbard, Democrat of Hawaii, resigned as a vice chairwoman of the Democratic National Committee on Sunday in order to endorse Senator Bernie Sanders for president.
The endorsement came a day after Hillary Clinton won the Democratic primary in South Carolina by a huge margin — she captured nearly 74 percent of the vote — in a signal of her support in the South right before several other Southern states vote in Tuesday’s primaries.
Ms. Gabbard explained her decision in a video on YouTube in which she said that, as a military veteran, she wanted the United States to avoid “interventionist wars of regime change.”