Eight 2020 Democratic presidential candidates are seen in a combination image from file photos (L-R top row): Billionaire Tom Steyer, U.S. Senator Elizabeth Warren, U.S. Senator Bernie Sanders and former U.S. Vice President Joe Biden (L-R bottom row): South Bend, Indiana Mayor Pete Buttigieg, former New York City Mayor and billionaire Michael Bloomberg, entrepreneur Andrew Yang, and U.S. Senator Amy Klobuchar. REUTERS/Files
