Nate Silver's latest forecast shows major swing state shifts

Nate Silver's latest election forecast shows two key swing states shifting in former President Donald Trump's favor over the past week, although Vice President Kamala Harris remains the favorite to win in November.

Trump received a series of positive polls in the final days of September in Pennsylvania and Michigan, the states Silver said have the greatest chance of influencing election results this fall.

In Pennsylvania, the former president led likely voters by 2.9 percentage points (51 to 48.1 percent) in an AtlasIntel poll conducted between September 20 and 25. FiveThirtyEight ranks America's top 25 pollsters in the 2024 election.

Trump also led Harris by 2 percentage points (48 percent to 45 percent) among likely voters in Pennsylvania in a poll conducted between September 26 and 29 by the conservative pollster Trafalgar Group.

In Michigan, a separate AtlasIntel poll also gave Trump a win, as he led by 3.4 percentage points (50.6 percent to 47.2 percent) among likely voters in a head-to-head race against Harris. Overall, Silver's forecast Monday showed Trump improving by 0.7 percentage points in Pennsylvania and 0.4 percentage points in Michigan over the past week.

Harris still leads on average in both battleground states, although Silver noted there is a significant gap between state polls and the vice president's overall lead in national polls. While Harris is ahead of Trump by 3.2 points as of Monday, according to Silver's tracking, she is ahead by just 1.2 points on average in Pennsylvania. Harris is also up 1.8 points in Michigan.

Silver pointed out in Monday's Silver Bulletin that the gap was a sign that the Electoral College “on net still represents a major disadvantage for Democrats.” Still, Silver's model still favors Harris winning the necessary 270 electoral votes in November, giving her a 55.1 percent chance of victory this fall. By comparison, as of Monday, Trump had a 44.7 percent chance of winning a second term in the White House.

Harris also has a slight lead in national polls, according to FiveThirtyEight's survey, with the vice president gaining an average of 48.5 percent to 45.7 percent as of Monday afternoon. With less than 40 days until Election Day, the race is far too close to declare a clear winner.

The 2024 race is expected to be one of the closest presidential races in U.S. history, and experts are closely watching the contests in seven states in recent weeks, even as results are expected in November, FiveThirtyEight's Geoffrey Skelley wrote in a report Monday will likely ultimately come down to a single “tipping point” state: Pennsylvania.

“Looking at the 538 forecast, Pennsylvania is the most likely tipping point state for the 2024 election under all scenarios,” Skelley wrote. “In 18 cases out of 100, the Keystone State provides the winning votes for either Harris or Trump.”

Silver also predicts that Pennsylvania has the highest chance of winning the election at 31 percent.