Democratic presidential candidate Andrew Yang exits Hopkinton Town Hall following a campaign event. (Photo by Scott Eisen/Getty Images) NEW YORK - Former Democratic presidential candidate Andrew Yang formally announced on Twitter Wednesday evening that he is running to succeed Bill de Blasio as Mayor of New York City."I moved to New York City 25 years ago," Yang said in a tweet announcing his candidacy. "I came of age, fell in love, and became a father here.