A new poll in Florida shows Democratic challenger Joe Biden opening up a double-digit lead over President Trump as new cases of the coronavirus surge in the battleground state.

The presumptive Democratic presidential nominee tops Trump 51-38 percent among registered voters in Florida, according to a Quinnipiac University survey conducted July 16-20 and released on Thursday.

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Biden’s lead is larger than in other polls conducted this month in the Sunshine State, which indicated the former vice president leading the GOP incumbent in the White House by a margin of 6 to 10 points.

An average of the latest polls in Florida compiled by Real Clear Politics gives Biden a 7-point advantage over Trump. The most recent Fox News poll in Florida – conducted last month – showed Biden topping the president by 9 points.

With 29 electoral votes, Florida is the biggest of the battleground states that will likely decide who wins the November election. Trump narrowly edged out 2016 Democratic nominee Hillary Clinton to carry the state four years ago. President Obama also won the state by razor-thin margins in his 2008 and 2012 election victories.

The Quinnipiac University poll indicates that Florida voters are giving both the president and Florida Gov. Ron DeSantis – a strong Trump ally – a thumbs down on how they've handled the pandemic. Fifty-seven percent say they disapprove of the governor’s handling of the public health crisis, with 59 percent disapproving of how Trump is responding to the crisis.

Those numbers are dragging down both politicians' overall approval ratings. Trump stands at 40-58 percent approval/disapproval in Florida, with DeSantis underwater at 41-52 percent approval disapproval.

“The president doesn’t escape the shifting moods and concerns of voters in Florida. His sagging numbers are a gut punch from one of the key states he keenly hopes to win,”  Quinnipiac University Polling Analyst Tim Malloy said in a statement.

The survey indicates Biden topping the president 89-2 percent among Democrats and 48-32 percent among independent voters – with Trump leading the former vice president 88-10 percent among Republicans.

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The poll’s release comes with three-and-a-half months to go until Election Day – which is still a long time in campaign politics. Florida allows for a week of early voting, which will take place Oct. 24-31. And the state will begin mailing out absentee ballots to voters during the last week of September. Florida – like virtually every other state in the nation – is expected to experience a surge in absentee balloting due to health concerns over in-person voting.

Eighty-three percent of those surveyed said the spread of the pandemic is a serious problem in the state, and in a separate question, 70 percent said the spread of COVID-19 in Florida is “out of control.” Nearly 8 in 10 questioned said that people in the state should be required to wear masks. And more than 6 in 10 said it would be too dangerous to send grade school students back in the fall.

The Quinnipiac Poll used live telephone operators to survey 924 self-identified registered voters in Florida. The survey’s sampling error is plus or minus 3.2 percentage points.

The president and his campaign have repeatedly slammed public opinion polling in recent months – arguing that they’re flawed and that they under-sample Trump supporters.