Washington (CNN) A recent poll found the majority of Democrats and Democratic-leaning independents remained undecided on their choice for next year's Democratic presidential primary.

The Washington Post-ABC News poll taken April 22-25 -- mostly before Vice President Joe Biden formally entered the race on Thursday, April 25 -- and released on Sunday found 54% of respondents did not name a specific candidate they would support.

No specific candidate in the crowded Democratic field commanded a major lead, although Biden led the pack at 13% of Democratic-leaning respondents saying they would support him were their state's primary or caucus held that day. Vermont Sen. Bernie Sanders received the second-most support at 9% of respondents, followed by South Bend, Indiana, Mayor Pete Buttigieg at 5%, California Sen. Kamala Harris at 4%, Massachusetts Sen. Elizabeth Warren at 4% and former Texas Rep. Beto O'Rourke at 3%. Others who Democrats and Democratic-leaning independents named in response to the question reached 1% of support or less.

The total number of Democratic candidates seeking to take on President Donald Trump has extended well into the double-digits, and Biden's formal entry into the race last Thursday added yet another expected heavyweight to the field just under a year out from the Iowa caucuses and months before the Democratic primary debates kick off this summer.

The Washington Post-ABC News poll had a margin of error ±5.5% points for its sample of 427 Democrats or Democratic-leaning independents.