Donald Trump loves recounting how everyone told him he wouldn't win in 2016, but he now has his work cut out to prove the doubters wrong a second time on November 3.
- Not a popular man -
Pollsters are more wary than four years ago, not least because this time the variables are off the chart.
Election season got into gear just as the coronavirus pandemic began sweeping through the United States, so far killing more than 170,000 people and pushing the previously booming economy off a cliff.
This has also been a summer of mass protests against racism, as the US faces a historic reckoning over racial injustice and police brutality.
And due to coronavirus restrictions, the challenger Joe Biden has barely been out of his Delaware home.
Despite the volatility, there is broad agreement that Trump has no chance of winning the popular vote, just like in 2016.
The Democrats' strongholds of California and New York alone give them millions of extra votes. Also, Trump is a historically unpopular president, with approval ratings jammed in the low 40s.
American University politics professor David Barker rates Trump's chances of a popular vote win at "maybe 1:100."
But US presidents are chosen via the state-by-state electoral college, not overall national tallies.
And in 2016, Hillary Clinton won nearly three million more votes than Trump, yet still lost the electoral college by a whopping margin. The Democrat got just 227 delegates to 304 delegates for Trump.
- Can he turn the tide? -
Trump often claims to have private polls showing him headed for a second term.
"Right now we're leading in so many polls that they refuse to put out," he said again Thursday.
The latest average of public, national polls from fivethirtyeight.com, however, has Trump down at about 43 percent to Biden's 51 percent.
The Economist's model, updated daily, currently gives Biden an 88 percent chance of winning the presidency, while Trump has just 12 percent. Its electoral college counter predicts a Biden landslide of 343 to Trump's 195, with only 270 required to win.
Republicans talk optimistically about a steep economic recovery in the next two months and maybe a dramatically early release of a coronavirus vaccine.
Others muse over the possibility of Biden self-sabotaging. He is renowned for awkward gaffes and has so far faced almost no difficult questioning from journalists.
An even less predictable factor is outside interference or a so-called "October surprise," like the Russian plot to destabilize Clinton's 2016 campaign and offer help to the Trump camp.
Allan Lichtman, an American University history professor whose "13 Keys to the White House" prediction method has worked accurately in every election since 1984 -- including 2016 -- says none of this can save Trump.
"A bolt from the blue is always possible, but it has not changed a prediction before," said Lichtman, whose "keys" look at structural political considerations, not polls.
"Even an improving economy is unlikely to change a key. We have an election-year recession and growth has been so negative that one more quarter is incredibly unlikely to reverse the call," he said.
- Roadmap -
Trump's campaign generals look at the map and still see numerous routes where an upset win here or there would put their man safely over the top.
Trump's collection of safe states alone is far from enough to reach the needed 270 electoral college votes.
So, as nearly always, the election will come down to voters in a handful of big swing states and maybe a scattering of smaller ones.
"We all need to win either Wisconsin or Michigan or Pennsylvania to win this thing again," Trump campaign manager Bill Stepien told reporters.
"If we win any of these three states and the states the president won in 2016, Joe Biden stays in his basement."
Barker says Trump really needs to keep hold of pretty much all the swing states that secured his 2016 win -- Wisconsin, Michigan, Pennsylvania, Florida, North Carolina and Ohio.
"He could lose one of any of those states and be fine, but not two."
In current polling, however, Biden leads in all those battlegrounds and even threatens in places like Texas where Trump won easily in 2016.
Asked to characterize Trump's path through the mounting electoral minefields, Barker answered: "narrow."