
With less than four weeks until Election Day, the race for the White House is tighter than ever.
Nationally, Kamala Harris remains a few points ahead of Donald Trump – a lead she has held since entering the race in late July.
But American elections are won or lost in the handful of states where both candidates have a chance of winning – those known as swing states.
The biggest prize among the seven swing states in this election is Pennsylvania, because it offers the highest number of Electoral College votes and therefore makes it easier for the winner to reach the 270 votes required to become president.
So what do the polls tell us about who might win?
Last July, polls looked bleak for Pennsylvania Democrats. Joe Biden’s numbers took a hit after his lackluster performance in the first presidential debate and Trump’s lead over him grew to more than four percentage points, as you can see in the chart below.
But when Harris’ campaign got underway, the Democrats’ fortunes quickly recovered. Once there were enough polls to calculate an average, data from polling analysis site 538 revealed that Harris had taken a small lead over her Republican rival.
Since then, she has maintained that lead – but not by much. Currently, the latest data puts Harris at 48% and Trump at 47.2%, one of the smallest leads in the Swing States.
When the margins are this fine, it’s impossible to know who’s actually ahead — especially when every poll conducted in Pennsylvania has a margin of error that means the numbers could be higher or lower.
If the polls are accurate and Pennsylvania is as close as they suggest, this shouldn’t be much of a surprise.
When Trump won the state in 2016 – the first time a Republican had done so since George HW Bush in 1988 – he did so by just 44,000 votes. Four years later, Biden took back Pennsylvania with 80,000 votes out of nearly seven million votes cast.
For Harris, the importance of winning the state couldn’t be clearer: No Democrat has won the White House without winning Pennsylvania since 1948. But for now, polls suggest the race will go down to the wire .

BBC Question Time comes to the US
- BBC’s flagship political debate program heads to Pennsylvania on Thursday October 10
- it comes from the National Constitution Center in Philadelphia, presented by Fiona Bruce and featuring a local audience
- panel includes BBC’s Anthony Zurcher, former Trump campaign adviser Bryan Lanza and commentator Mehdi Hasan
- it will be broadcast on the BBC website from 4:00 p.m. EST (9:00 p.m. BST)
- UK audiences can also watch on BBC One and iPlayer, and global audiences on the BBC News channel.

