Donald Trump could win a landslide victory by taking previously Democratic safe seats, new polling has showed.

The presumptive Republican presidential nominee is set to face the incumbent president in November, and polls have so far shown that the results of the 2020 White House rematch will be tight, with the pair statistically tied or holding only marginal leads in a number of surveys.

However, a polling memo leaked to Puck News has suggested Trump, the former president, could win a number of states, including New Hampshire, Virginia and New Mexico, which could lead him to win the election.

The polling found that, in a race including third-party candidates, the Democrat has fallen by around two points in every battleground state. In Pennsylvania and Michigan, he is behind Trump by seven points. He is also losing by 10 points in Georgia and by nine points in Nevada.

It found that he is now 0.6 percent behind Trump in Virginia and 0.5 percent behind him in New Mexico. It also found that Trump is now 2.8 percent ahead in New Hampshire.

Biden won all of these states in the 2020 presidential election.

The memo was compiled by the progressive nonprofit OpenLabs and was conducted after the president participated in the first presidential debate where he was met with criticism over his performance.

Newsweek has not obtained a copy of the polling for verification and has contacted Biden's campaign by email outside of normal business hours to comment on this story.

The poll also found that 40 percent of people who voted for Biden in 2020 now think he should end his campaign. In March, 25 percent of Biden 2020 voters said he should drop out.

Surveys like these are significant due to the U.S.' Electoral College system which awards each state a certain number of votes based on population.

A presidential candidate must secure 270 electoral votes for victory, and winning the national popular vote does not guarantee success.

If correct, the polling shows that Trump could win 333 Electoral College votes to Biden's 205, according to analysis of the data.

However speaking to Newsweek, Todd Landman, a professor of political science at the University of Nottingham in the U.K., said average polling was more accurate than a single poll.

"I prefer looking at www.fivethirtyeight.com, which uses adjusted averages across numerous polls instead of relying on one single poll," he told Newsweek.

"These data show that Mr. Trump leads in Arizona by 5.1%, Georgia by 6.7%, Michigan by 2%, Nevada by 3.9%, Pennsylvania by 1.9%, and Wisconsin by 1.0% as of July 2, 2024. These data temper some of the numbers from any one poll, but do not bode well for the Biden campaign if they hold until November," he said.

"The SCOTUS [Supreme Court] decision on Mr. Trump's immunity, however, means that his sentencing in the Manhattan case will be delayed as the court examines the possibility of the inadmissibility of some evidence and will see an evidentiary hearing in the January 6 case, where the D.C. court needs to adjudicate what constitutes 'official acts' of the former president," Landman said.

"This evidentiary hearing will likely occur very close to the November election and may sway voters in the late stages of the campaign."

A second debate between the two candidates is scheduled for September 10. Then, on November 5, voters are set to cast their ballots for the next president.