Score another Kennedy for the Barack Obama campaign.

Maria Shriver, wife of Governor Arnold Schwarzenegger of California and daughter of Eunice Kennedy, endorsed Senator Obama Sunday night in Los Angeles. Her husband, a Republican, endorsed Senator John McCain last week.

It was the latest development in the battles of the Kennedys in the presidential race. She appeared as a surprise guest at a rally in Los Angeles for Mr. Obama with Michelle Obama, Oprah Winfrey and Caroline Kennedy.