WHITE SUBURBAN WOMEN
Despite Mr Trump's direct appeals to "the suburban housewives of America" with promises to "save" their neighbourhoods, white women living in the suburbs have moved away from Mr Trump since 2016. But enough of them might support him in swing states for him to eke out a narrower win this year.
Sara Tanner, 39, housewife Elkhorn, Wisconsin
VOTING FOR TRUMP
Most important issue for her: Being pro-life
Why Trump appeals to her: His honesty and pro-life position
I think it's okay to protest. I think when it comes to burning things down, destroying property, throwing rocks at windows, that is no longer protesting, that is rioting. I 100 per cent support law and order and I think funding the police is super important. I think they need, if anything, more training, more resources, so they can continue doing the great job they're doing.
WHITE BLUE-COLLAR VOTERS
Representing Mr Trump's base, white voters without college degrees are solidly behind him. But they need to turn out in numbers matching - or indeed, exceeding - those who turned out in the last election to seal the deal for him.
James Crow, 65, former Marine and now a local pickup and delivery driver Gastonia, North Carolina
VOTING FOR TRUMP
Most important issue for him: The economy and the right to bear arms
Why Trump appeals to him: His stewardship of the economy
There needs to be some police reform, he (Mr Trump) admits that. The George Floyd incident was horrible. But you can't de-fund the police.
MR JAMES CROW, explaining his position in regard to the George Floyd incident, where an unarmed black man was killed by a police officer, prompting calls for police reform.
SENIORS
If there is one group that has swung the hardest from Mr Trump to Mr Biden, it is seniors. This could spell trouble for the President as they are also disproportionately represented in battleground states, as well as being the ones most likely to turn up to vote.
Joe Clouse, 77, retired school district superintendent Miami, Florida
VOTING FOR BIDEN
Most important issue for him: Sustaining social security
Why Biden appeals to him: His compassion
I think you have to be a compassionate president. You can't be one that bullies or dictates. It has upset so many people with what's going on because he (Mr Trump) has been unrealistic and unprofessional.
MR JOE CLOUSE
LATINO VOTERS
Latinos are one of the fastest-growing voter groups and one of the most diverse. Overall, they mostly lean Democrat, although Republicans have been making real inroads over the years. In swing states like Florida, where they make up 20 per cent of the population, their support could hand Mr Trump or Mr Biden an Electoral College victory.
Christian Chavez, 27, flier distributor Washington, DC
VOTING FOR BIDEN
Most important issue for him: Immigration
Why Biden appeals to him: His decency
He (Mr Trump) knew about it (Covid-19), he just didn't want to care about the United States. He didn't care about the people, he just cared for himself. That's the only thing he's there for, for himself.
AFRICAN-AMERICANS
Black voters, particularly older women, overwhelmingly back Mr Biden. But Mr Trump has been gaining some ground among younger voters and men, and if he manages to shave off some of Mr Biden's support from this group, it might be enough for him to win some crucial swing states.
Alysa C, 34, works in photography and graphic design Prince George's County, Maryland
VOTING FOR BIDEN
Most important issue for her: African-Americans' rights and women's rights
Why Biden appeals to her: He is better informed on race issues.
In the first debate, Trump pretty much said 'we don't need racial sensitivity training, I don't care for it, it doesn't represent American values'. As a black person watching that, it broke my heart. It made me feel like he was saying he didn't care about black people and didn't want to hear their perspective at all. I don't have patience for that.
MS ALYSA C