Virtually all recent polling shows Joe Biden far ahead, both nationwide and in key battleground states. Still, even microscopic changes in the electorate could sway the election toward Trump, some Democrats fear.
Guy Cecil, the chairman of the largest Democratic Super PAC Priorities USA, said that there are still fears Trump could pull off another upset.
"Am I optimistic? Yes. But I do continue to have serious concerns and we need to continue to run through the finish line."Priorities USA's own data contradicts public polling and shows Trump ahead in states such as Iowa, Texas and Ohio.
Furthermore, according to Cecil, if turnout among people of color and white, working-class voters is lower than expected, Trump could take North Carolina, Florida and Arizona. In addition, races in states like Michigan, Nevada and Pennsylvania would become toss-ups.
"If the election were on Tuesday, Joe Biden would win. But the election is not on Tuesday and … every day feels like an eternity, so we've got to keep working through," Cecil said.
Democratic pollsters John and Jeremy Zogby recently suggested that the presidential race is much closer than it seems. They argued that most major research agencies and news organizations underestimate Trump's support because they oversample Democrats.
Pollster and strategist Chris Kofinis expressed similar sentiments, noting that the contest is still volatile because Americans are becoming increasingly frustrated with the political system as a whole.
"Democrats need to be incredibly cautious and remember the ghosts of 2016. Honestly, who gives a damn about the polls," Kofinis argued. "Models show Biden with a 85 percent chance of winning. Would you get on a plane that had 15 percent chance of crashing?"
Indeed, FiveThirtyEight's polling model gives Biden an 85 percent chance of winning. The same model predicted a Clinton victory in 2016, but Trump cruised to the White House after carrying key Rust Belt battlegrounds.
On the other hand, as The Hill noted, Clinton was widely disliked. Biden does not seem to have that problem. In fact, key voter groups that voted red in 2016 -- suburbanites, independents, and seniors -- now seem to be leaning blue.
Even the voters who dislike both candidates seem to prefer Biden, which was not the case for Clinton in 2016.
According to a CNN survey released earlier this week, Biden's favorability ratings have improved and he has managed to make inroads with moderates, independents, young people and women.