Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Biden Remains Atop a Shifting Democratic Field Jim Malone WASHINGTON - The Democratic presidential field continues to shift as one candidate dropped out this week and another joined an already crowded group hoping to oust President Donald Trump from office next year. At the top of the field, former Vice President Joe Biden remains the leading contender but finds himself fending off increasingly strong challenges from two senators--Kamala Harris of California and Elizabeth Warren of Massachusetts. And 2016 contender Senator Bernie Sanders continues to lurk in the top tier, offering liberal voters one of several candidates to choose from. The latest to join the Democratic race is billionaire liberal activist Tom Steyer who made his candidacy official in a campaign video. "If you think that there is something that is absolutely critical, try as hard as you can and let the chips fall where they may. And that is exactly what I am doing." Steyer had been funding a grass roots effort to build support to impeach President Donald Trump and some months back decided against a presidential run. Now Steyer is in the field but will have to scramble to make the cut for some of the upcoming Democratic debates. .