Former Vice President Joe Biden and Sen. Bernie Sanders of Vermont top the list of favored Democrats to run for president in 2020, according to a new poll of likely Iowa caucusgoers.

The CNN/Des Moines Register/Mediacom poll said 27% favored Biden and 25% favored Sanders.

The two Democrats were the only to crack more than 10% support, out of a field of 20 potential candidates.

Former Vice President Joe Biden and Sen. Bernie Sanders of Vermont are far and away the favored Democrats to run against President Donald Trump in 2020, according to a new poll of likely Democratic caucusgoers in Iowa released Saturday evening.

The CNN/Des Moines Register/Mediacom poll surveyed 401 likely Democratic caucusgoers between March 3 and 6, with a striking 27% favoring Biden and 25% favoring Sanders.

The two Democrats were the only to crack more than 10% support, out of a field of 20 potential candidates. Sen. Elizabeth Warren of Massachusetts was the next most favored candidate, with 9% of respondents saying she was their top pick, and 7% saying the same for Sen. Kamala Harris of California.

Former Rep. Beto O'Rourke of Texas received 5% support, while Sen. Amy Klobuchar and Cory Booker, from Minnesota and New Jersey, respectively, were the top choices for 3% of the respondents. The poll has a margin of error of plus or minus 4.9 percentage points.

Senator Bernie Sanders speaks during a news conference on Yemen resolution on Capitol Hill in Washington, U.S., January 30, 2019. Yuri Gripas/Reuters

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The numbers are akin to those released for the same poll conducted in December 2018, which also showed Biden and Sanders as the top two favorites.

Back then, 32% of poll respondents said Biden was the first choice for president, and 19% said Sanders was. O'Rourke was the only other Democrat to break double digits back then, with 11% saying he was their top pick.

Biden has not yet declared that he's running for president, but Sanders announced his campaign last month.

Though Biden dropped several percentage points from the December poll, the numbers should still be encouraging to him, according to J. Ann Selzer, president of the Des Moines-based Selzer & Co., which ran the poll.

"If I'm Joe Biden sitting on the fence and I see this poll, this might make me want to jump in," Selzer told The Des Moines Register. "I just can't find much in this poll that would be a red flag for Joe Biden."