WASHINGTON – Former Vice President Joe Biden and Sen. Bernie Sanders, I-Vt., are each besting President Donald Trump in head-to-head matchups in a new Florida poll released Tuesday.

The president won the state with a 1.2% margin — or 112,911 votes — with 49% of the popular vote compared to Democrat Hillary Clinton at 47.8%. He's back in the state Tuesday to formally launch his 2020 re-election bid as the battleground state is critical to winning the White House.

Biden is leading against Trump, 50% to 41% in a head-to-head matchup, according to a Quinnipiac University poll. Sanders holds a 6-percentage point lead, 48% to 42%, in a matchup against the president

Trump is also locked in four other too-close-to-call matchups against other top-tier 2020 Democrats, all of which are within the margin of error.

More:From outsider to incumbent: Donald Trump launches re-election campaign with rally in Florida

Sen. Elizabeth Warren, D-Mass., is at 47% compared to Trump at 43%; 45% of those surveyed support Sen. Kamala Harris, D-Calif., to 44% for Trump; former Rep. Beto O'Rourke, D-Texas, is at 45% to Trump's 44%; and South Bend, Ind., Mayor Pete Buttigieg is at 44% compared to Trump at 43%.

'We have to do better': Orlando paper posts scathing editorial ahead of Trump's big visit

More: Fans line up early for Donald Trump's Orlando rally despite heat and possible thunderstorms

There is a margin of error of plus or minus 3.3 percentage points, with 1,279 Florida voters surveyed between June 12 to 17. In addition, there is a margin of error of plus or minus 5.8 percentage point among the 417 registered Democrats surveyed in the poll.

In the 2020 Democratic primary race, Biden is the leading candidate among registered Democratic voters in Florida, holding an over 25 percentage-point lead compared to the next candidate, Sanders. Biden is at 41%, according to Tuesday's poll. Sanders then follows at 14% and Warren at 12%. Buttigieg is the next candidate at 8%, then Harris at 6%. Only three other candidates polled with voters, all of which were at 1%: O'Rourke, Sen. Cory Booker, D-N.J., and Sen. Amy Klobuchar, D-Minn.

Tuesday's poll is not the first to suggest that the president could be facing a challenging environment with voters in the 2020 election.

Trump has been trailing Biden, as well as a number of other candidates, in several match-up polls. Last week, Quinnipiac released a separate poll that showed Biden holding a 13 percentage-point lead nationally with voters over Trump, 53% to 40%.

But he wasn't the only candidate to lead over Trump in that poll.

Sanders had a 9 percentage-point lead over Trump, 51% to 42%; Harris held an 8-point lead, at 49%, compared to Trump's 41%. Warren topped Trump 49% to 42%. Buttigieg and Sen. Cory Booker, D-N.J, held a 5 percentage-point lead against Trump, with each at 47% to Trump's 42% in both of those matchups.

Earlier this month, Quinnipiac also showed tight matchups between Trump and seven Democratic candidates — Biden, Warren, Sanders, O'Rourke, Buttigieg, Harris and former San Antonio, Texas, Mayor Julian Castro — in Texas, a traditionally conservative state.

Despite the tight matchups in Florida, the president's approval rating with Florida voters is the best since he was elected. According to Tuesday's poll, 44% of those surveyed approve of the job Trump is doing as president, compared to 51% who disapprove. In a March 14 Quinnipiac poll, Trump's approval rating was at 41% and disapproval was at 53% in Florida.

An interactive guide:Who is running for president in 2020?

'We're off and running':A look at Donald Trump's un-Trumpian campaign for reelection in 2020

Trump's own internal campaign polling also reportedly indicated that Biden is leading the president in several key states.

Trump's presidential campaign also reportedly fired some of its pollsters after internal polling showed Trump losing to Biden in a hypothetical matchup in battleground states.

Trump trailed Biden by double digits in the key swing states of Wisconsin, Pennsylvania, Florida, and Michigan, according to polling numbers obtained by NBC News. The NBC report follows a Politico report that the president's campaign was targeting and seizing on possible opportunities in New Mexico, Nevada and New Hampshire following internal polling suggesting that Biden was ahead in key, battleground states in the Rust Belt. Trump relied heavily on those Rust Belt states to beat Clinton in 2016.

The president repeatedly denounced polling during the 2016 cycle, and is again criticizing polls as seeks re-election in 2020.

"Only Fake Polls show us behind the Motley Crew," Trump tweeted Monday morning . "We are looking really good, but it is far too early to be focused on that. Much work to do! MAKE AMERICA GREAT AGAIN!"