New poll reveals Joe Biden is the only Democratic 2020 candidate who would beat Trump in a presidential election outside the poll's margin of error

• Former Vice President Joe Biden is the only Democratic candidate that would defeat Trump outside the margin of error of a recent poll
• Of all likely voters, 49 per cent said they would vote for Biden, while 38 per cent say they would vote for Trump
• Two other candidates in the poll, Massachusetts Senator Elizabeth Warren and Vermont Senator Bernie Sanders, beat Trump, but fell within the 3 percentage point margin of sampling error
• Trump said the four front-runners in the Democratic primary race are Biden, Sanders, South Bend, Indiana Mayor Pete Buttigieg and former Texas Congressman Beto O'Rourke
• All the candidates Trump thinks he could face in 2020 are white men
• Warren says he 'would like it to be that way'

Democratic front-runner Joe Biden is the only primary candidate who would beat President Donald Trump outside the margin of error in a new poll published Thursday.

The Fox News poll has the former vice president leading Trump by 11 points in hypothetical 2020 matchups.

Among all registered voters, 49 per cent say they would vote for Biden if he were up against Trump in 2020, with 38 per cent saying they favor the incumbent president.

The poll was taken May 11-14 and has a margin of error of 3 percentage points, it does not state what percentage of respondents are registered Democrats, Republicans or independents. 

Biden is the only one who defeated Trump outside the margin of sampling error in the poll, and the only candidate that pushed the president's support below 41 per cent. 

Two other candidates, Vermont Senator Bernie Sanders and Massachusetts Senator Elizabeth Warren also beat Trump in the poll, but fell within the margin of error.

Sanders earned 46 per cent of the vote in his matchup compared to Trump's 41 per cent, and 43 per cent of registered voters said they would vote for Warren if she faced Trump, while only 41 per cent said they would prefer Trump.

California Senator Kamala Harris tied with Trump, both earning 41 per cent of the vote, and South Bend, Indiana Mayor Pete Buttigieg trailed the president 40 per cent to 41 per cent.

Biden emerged as a clear front-runner in the 2020 race, even before he officially announced he was running in late April.

He regularly polls first among the crowded field of Democratic primary contenders, which grew to 24 this week when former New York Mayor Bill de Blasio announced he was entering the race.

In the poll, 38 per cent of respondents say they would reelect Trump and 54 per cent say they would back someone else if they 2020 elections were held today.

Trump said it appeared the Democratic primary race was down to four candidates, all white men.

He said on Tuesday he would either face Biden, Sanders, Buttigieg, or former Texas Representative Beto O'Rourke, who didn't even make the top five in the Fox News poll.

He mocked the candidates as 'Crazy' Bernie Sanders, 'Sleepy' Joe Biden, 'Reboot' Beto O'Rourke and 'Boot-Edge-Edge,' a play on the openly gay mayor's hard-to-pronounce last name.

The front-runner in the president's mind, however, is still Biden, who he predicted he would likely face in the 2020 presidential elections.

When Warren, who defeated Trump in the poll, was asked Thursday at a rally in Fairfax, Virginia about Trump's assertion that he would likely face a man in 2020, she told Dailymail.com that he 'would like it to be that way.'