Factbox - Crowded Democratic field vies for 2020 U.S. presidential nomination

Former U.S. Vice President Joe Biden announces his candidacy for the Democratic presidential nomination in this still image taken from a video released April 25, 2019. BIDEN CAMPAIGN HANDOUT via REUTERS ATTENTION EDITORS - THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. NO RESALES. NO ARCHIVES

WASHINGTON (Reuters) - The largest Democratic field in the modern U.S. political era is competing for the party's 2020 presidential nomination.

The diverse group of 20 vying to challenge President Donald Trump, the likely Republican nominee, includes six U.S. senators. A record six women are running, as well as black, Hispanic and openly gay candidates who would make history if one of them becomes the party's nominee.