With 3 months* to go to the US elections, here's why I reckon that Biden should be a much stronger favourite than the betting markets make him [Thread]

* Although polling starts much earlier than Nov 3. Early ballots can be cast in September in some states. This itself matters.

1. The place to start is with the national picture, which is that Biden leads by a lot. The RCP average has him 8.4% ahead. If the election was today (and the polls are right), then Biden could be looking at a landslide win with 400+ ECVs.

2. To put the 8.4% Biden lead in context, these are the winning margins of the last 6 US presidential elections.

1996 Clinton +8.5
2000 GW Bush -0.5
2004 GW Bush +2.4
2008 Obama +7.2
2012 Obama +3.9
2016 Trump -2.1

Clinton and Obama won 379 and 365 ECVs respectively.

3. It is true that you can win the Electoral College without winning the popular vote; it's not possible to win from this far back. For Trump to be re-elected, he needs to cut Biden's lead to at most the 2% that Hillary had in 2016.

4. However, as things stand, it's far from certain that Trump could repeat 2016 even if he did poll the same national numbers as that election. Biden's lead in NY and California is only about the same as Hillary's: there's a disproportionate improvement elsewhere.

5. And that's borne out in the swing state polling. Biden leads by 5% in Wisconsin, 8% in Michigan, 7% in Pennsylvania and 8% in Florida. Those four states alone represent 75 ECVs and would just about reverse the Electoral College result from 2016.

6. In truth though, it's a lot worse for him than that. Trump is in danger of having done to him what he did to Hillary in 2016: getting outflanked through what should be safe states. He currently leads by only 0.2% in Texas and trails by 4% in Arizona, for example.

7. The other really serious difficulty for Trump is the consistency of Biden's lead.

Even if Trump can win with a 2% national deficit (which as mentioned above is doubtful), he's *never* got that close since head-to-head polling began a year ago; his best is a 4% deficit.

8. That consistency of the Biden lead is a marked difference with the 2016 race. It is true that Hillary also had some big leads (6% in mid-Oct, for example), but they were never solid: Trump led in May and July, and was within 3% through most of Sept and in late Oct.

9. The most revealing stats behind those headline polling figures are in Trump's favourable / approval ratings.

Although his net approval rating of -13 is not awful by historic standards overall, it is low for a president three months out from seeking re-election.

10. Also, again unlike 2016, Trump's favourable rating lags well behind his opponent. He was fortunate in 2016 that Hillary was so polarising. Biden, by contrast, has a net favourable rating of -2. While that's not the same question and not a great score, it's still revealing.

11. Also no doubt behind the stickiness of Biden's lead overall is the polarization of Trump's approval: a very large proportion of those who like him, love him; and of those who dislike him, hate him. There simply aren't very many swing voters.

12. Still, while some of those stats do point to the polls being predictive, they are still a snapshot of now (and of the past), not of how things will be in November. So what might change the situation over the next three months?

13. Biden's VP pick shouldn't be a game-changer unless he goes with someone a lot of voters would worry about as president - which particularly matters given Biden's age. Everything coming out of the campaign suggests he is aware of that risk.

14. The debates might also shift the polling though to me, the bigger risk here is for Trump. Biden came through 11 debates during the primaries: he has been tested in the format and in small fields, performed well. I think Republicans are setting expectations of Biden low.

15. The Trump-Biden debates will be different from the Dem primary ones in the Trump will be far more aggressive. That, however, is predictable and can therefore be prepared for. It's also unlikely to appeal to such swing voters as there are.

16. Relatedly, there is the risk that either candidate might make a serious gaffe or a election-ending scandal might emerge but in truth, the chances are low simply because so much is known and the bar for what would count under either measure is now so high.

17. Away from the pure politics, Trump's best chances are if the US can solve both the Covid-19 epidemic and the economic problems that come with it in the next two months. Both issues will dominate and Trump's handling is badly viewed. Unless he can turn that round, he loses.

18. Personally, I don't think Trump can change tack on Covid-19 both because it's against his personality to admit such a major error and also because a U-turn would run against the strong instincts of his core support. And if he can't, that alone dooms him.

19. Indeed, we're *already* reaching the point where the Covid numbers will be affecting votes cast in real time.

Hospitalization numbers depend on the balance of admissions / discharges, and severe cases today will likely still be in hospital when early voting opens.

20. Overall then, while Trump does have chances to change the election's narrative, the fundamentals are running strongly against him and those chances are largely ones out of his control or which come with big risks of their own.

I don't give him more than one chance in six.