Two new polls show Joe Biden maintains his months-long lead over Donald Trump in key battleground states with just 48 hours to go in the race.

In one of those states, Wisconsin, Mr Biden’s 11-point lead looks virtually insurmountable.

The New York Times is reporting Mr Biden has “a clear advantage” in these states.

Meanwhile, early voting nationwide is astonishing and total turnout will be huge, always a good sign for Democrats.

The country’s top polling analyst, who sorts and weighs dozens of state and national polls, has given Biden a 90 percent chance of winning as of early Monday morning (Australian time).

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“Trump,” he said, “has to run the table” to win.

So why are Democrats so miserable?

“Democrats at all levels remained privately terrified of another surprise result,” reported the Washington Post, “despite far greater confidence in polling that pointed to a victory for former vice president Joe Biden.”

Biden campaigned with former President Obama on Saturday in Michigan, a battleground state that Trump narrowly won in 2016. Photo: Getty

That same home page described Mr Biden’s 6-point lead in Pennsylvania as “slight,” and included a separate story headlined “Democrats Grow More Anxious about Pennsylvania.”

As I read those stories at home in the US on Sunday morning (local time), my partner – doomscrolling in the bedroom – texted me an article she’d just read in the New York Times about the Trump campaign’s “three-pronged strategy” to wreak havoc with Pennsylvania’s mail-in ballots.

“Had you read this?” she asked.

I confess I hadn’t. Deliberately. My tolerance for apocalyptic news stories was fraying, and it was barely 9 a.m.

Beyond the psychological self-defence, there are practical reasons for Democrats to stay scared through Tuesday. Get-out-the-vote phone banks and texting operations can lure more volunteers over the next two days if supporters think the sky is falling.

Even if a majority of the 90 million votes cast around the country are Mr Biden’s, they’re already in bank. It’s time, the thinking goes, to run up the score.

Here’s a list of some of the things that will keep Democrats up for the next two nights:

Possible Polling Errors

After 2016, pollsters noodled with their models, trying to better weigh the electorate, particularly the effect of education on their results. The polls were on the money in the 2018 congressional races, but the presence of Mr Trump on the ballot changes things. That said, polls have been stable for month:  a sign of voter decisiveness, or something like a car’s fuel gauge stuck and no longer working?

Mail-in Vote Challenges

It’s inevitable that thousands of ballots will have been incorrectly filled out, depending on the signing and return requirements in each state (“naked ballots” will be the “hanging chads” of 2020, I guarantee you).  Just how many ballots get bounced will depend in part on how aggressive GOP operatives challenge them. This could take a while: Pennsylvania, for example, had 3 million requests for mail-in ballots, and less than half had been returned by Sunday. And state officials aren’t allowed to start counting them until Tuesday morning.

And that’s just one state.

An election worker carries mail-in ballots in US Postal Service containers to be processed by election workers. Photo: Getty

GOP Turnout

Mr Trump has urged his supporters to keep their powder dry until Election Day. Whether that’s enough to overcome the Democrats’ early vote lead will vary county to county, state to state. But you can be sure television footage of MAGA-hatted voters lined up around polling places, pumping their fists and expressing confidence, will drive Dems to despair throughout the day on Tuesday (local time).

General Election Day Chaos

Broken machines, COVID-19 protocols, carpark fistfights, even the weather: this election day will be like no other. Add to that the counting of all those mail-in ballots, and it’s certain some states—like Pennsylvania—will not have results Election Night. Whether results in other states can compensate for that uncertainty is, well, uncertain. Unless it’s a blowout either way, this could take days to sort out.

E Pluribus Unum Duo

Prevailing over this election is the sense that Americans no longer know how their neighbours think. The media silos and echo chambers isolate and disorientate, leaving people less able to gauge just how big the other side is.

If this country could pick Mr Trump once before without me ever expecting it, some Dems fear, they could do it again.

The lack of dialogue creates not just anger and fear, but real uncertainty—of polls, probabilities and people.

Larry Hackett is the former editor-in-chief of People magazine, and a contributor to the US morning television news program Good Morning America