10 days to go: A final preview of the United States election

6 weeks ago, I previewed the United States presidential election (part 1 here and part 2 here). Now with 10 days to go (polls begin closing on the morning of Wednesday 5^th November Australian time), I will provide a final overview of where the race for the presidency stands. I will also provide a brief update on the Senate election, which I previewed four weeks ago.

As per my previous posts, I will be using FiveThirtyEight’s weighted polling averages for the presidential election and FiveThirtyEight’s Senate forecast for the Senate, as of Saturday 24^th October.

Overview

In my last post, I noted that there are three ways Trump could still win despite being behind in the polls: a narrowing in the polls, a large polling error or undemocratic interference in the electoral process.

Now there are only 10 days to go. Has Trump narrowed Biden’s lead in the polls enough to put him within striking distance?

The answer is a resounding no. Far from narrowing, Biden’s lead has actually increased. 6 weeks ago, Biden led the national polls by 7.6 points. Today he leads by 9.7 points. If Biden wins by this margin, it would be the biggest popular vote victory of any presidential candidate since Ronald Reagan’s re-election in 1984. 

There is precious little time left for Trump to turn this lead around and only about 5% of voters are still unsure who to vote for. And with around 48 million people having already voted (that’s about one third of all votes cast in 2016), the pool of potential voters for Trump is shrinking fast.

Of course, the national popular vote does not actually determine the winner of the election – the electoral college does (read my previous post on this subject for an explanation of the process). So let’s dive into the latest state polling to get a better idea of the likely result in the electoral college.

Note: in my previous post on this subject, out of an abundance of caution, I included a section on swing states where Biden led by 10-15 points, including states like Virginia and Colorado. With just 10 days to go, it is clear that these states are not going to be competitive this year, so I will not be including them in this post.

Swing states where Biden leads by 5-10 points:

• Minnesota: 7.9 points to Biden
• Michigan: 7.6 points to Biden
• Nevada: 6.5 points to Biden
• Wisconsin: 6.5 points to Biden
• Pennsylvania: 6.1 points to Biden

The first thing you will notice about these states is how similar the margins are compared to 6 weeks ago: the polling has been remarkably stable. Biden’s lead in the Clinton-won states of Minnesota and Nevada is slightly up, while Biden’s leads in the Trump-won states of Michigan and Wisconsin are exactly the same as they were six weeks ago, to the decimal point. The crucial state of Pennsylvania has improved for Biden by 1 point. Biden leads in these five states by between 6 and 8 points, a very solid lead (a polling error may endanger these leads but it would need to be a pretty large polling error). Simply winning these states is enough for Biden to be elected president. 

There are two other states where Biden was leading by 5-10 points six weeks ago: New Hampshire and Arizona. Biden’s lead in New Hampshire (which Clinton won in 2016) has increased by 3.5 points to 11.4 points, putting the state beyond Trump’s reach. Arizona we will come to momentarily.

Swing states where Biden or Trump lead by less than 5 points:

• Florida: 3.3 points to Biden
• Arizona: 3.2 points to Biden 
• North Carolina: 2.9 points to Biden
• Iowa: 1.3 points to Biden
• Georgia: 1 point to Biden
• Texas: 0.5 points to Trump
• Ohio: 1 point to Trump

This group of close states has also been fairly stable but they have generally moved slightly in the direction of Biden over the last six weeks (reminder: Trump won all these states in 2016). Georgia and Iowa have moved towards Biden by 2.5 points and 2.9 points respectively, giving Biden the lead in both states (but they are still very close).

Biden’s lead in North Carolina has increased by 1.5 points to 2.9 points, while Florida has also shifted slightly in Biden’s direction. It is a good sign for Biden that his leads in both these states are up to around 3 points.

Trump still leads by the narrowest of margins in Ohio (by 1 point) and Texas (0.5 points), with both states hardly budging since six weeks ago. 

Arizona is the outlier here: it is the only one of these states that has swung towards Trump. Biden had lead by 5 points in Arizona six weeks ago but that lead has shrunk by 1.8 points to 3.2 points. I cannot offer an explanation for this, although it is notable that the southern states of Florida, Arizona and North Carolina are all now polling within half a point of each other.

So let’s briefly summarise:

• Biden is leading in the mid-western states of Minnesota, Michigan, Wisconsin and Pennsylvania by 6-8 points. He is also leading in south-western Nevada by 6.5 points.
• He is leading in the southern states of Florida, Arizona and North Carolina by around 3 points.
• Iowa and Ohio in the mid-west, and Georgia and Texas in the south could go either way.

If Biden wins all of these states, this would result in Biden winning the electoral college 413 to Trump’s 125*, a margin of 288 and the biggest win in the electoral college since George HW Bush’s election in 1988 (he won by 315).

States where Trump leads by 5-10 points:

• Alaska: 5.7 points to Trump
• Missouri: 6.5 points to Trump
• Nebraska*: 7 points to Trump
• South Carolina: 7.1 points to Trump
• Montana: 7.7 points to Trump
• Kansas: 8.9 points to Trump

There has been hardly any movement in these states over the last six weeks (excluding Alaska and Nebraska, which did not have polling averages when I wrote my previous post). Kansas and Montana have weakened slightly for Trump, whereas South Carolina has slightly strengthened. Missouri has not budged.

Trump is favoured to win these states but I include them because just as a significant polling error could cost Biden his lead in states like Pennsylvania and Wisconsin, a significant polling error could cost Trump his leads in these states. 

Summarising the presidential race

Trump is very far behind in the polls. Before turning to the Senate, let’s return to the three ways Trump could win.

A narrowing of the polls? As discussed earlier in this post, Trump has been losing ground in the polls over the last six weeks. As every day passes, and millions more Americans vote, the probability of the polls tightening shrinks further. Is it possible Trump makes up lots of ground in the last 10 days of the campaign? Yes. Is it likely? Nope.

A major polling error? Biden’s national vote lead of 9.7 points is so large, Trump needs a polling error to be more than a large error; he needs it to be a gigantic, once-in-a-generation polling screw-up. The state polls are a bit closer, with Biden leading in the crucial tipping point states by 6-8 points. A large polling error could cost Biden his leads in these states but the polling error would have to be very widespread, costing Biden his leads in not just Michigan, Wisconsin and Pennsylvania but also Florida, Arizona, North Carolina, Iowa and Georgia. Possible? Yes. Likely? Probably not. And remember, a polling error is as likely to benefit Biden as it is to benefit Trump.

Election shenanigans? This continues to be a bit of an unpredictable wildcard but again, if the polls are right, Biden’s polling lead is so large that literally millions of votes would have to be tossed out to change the result. That would require a very extensive and sophisticated rigging operation. Possible? Yes. Likely? Who knows, but my gut says that it is very unlikely.

The Senate race is still close but Democrats are edging ahead

Now for a brief Senate update. The race for the Senate has remained tight and fairly stable since my last post on this subject four weeks ago but a number of key races have shifted slightly in the direction of Democrats, improving their odds of gaining a Senate majority.

(Reminder: for the Senate, I use FiveThirtyEight’s probabilistic forecast of the Senate, not polling averages. Eg. Republicans have a 78% chance of winning Alabama; 78% is the probability that a party will win, not the size of the winning margin).

Republicans are still favoured to win Alabama off Democrats, with a 78% chance (up 1%). Republicans also have a 21% chance of winning Michigan from the Democrats (down 1%). These races have hardly changed since my last post.

Democrats are still favourites to win four Republican Senate states, with their lead in Colorado in particular increasing over the last few weeks. Democrats have an 83% of winning Colorado (up 12%), a 78% of winning Arizona (up 1%), a 64% chance of winning North Carolina (up 1%) and a 62% chance of winning Maine (up 3%).

Democrats have also pulled ahead in two Republican-held seats that may be crucial to delivering the Democrats a Senate majority: Iowa and Georgia. Iowa continues to be a tossup race but Democrats have their noses in front with a 56% chance (up 9%). The most substantial change in any Senate race has been in the Georgia special election, with Democrats chances improving significantly from 19% to 54%. I recommend reading this article if you want to understand why. In short, the Georgia special election is a case study of the dangers of pandering to your base when the vast majority of voters are not in your base.

Democrats are underdogs in another six races currently held by Republicans but they have improved their chances in five of these races: they have a 32% chance in Montana (down 2%), a 29% chance in the regular Georgia election (up 3%), a 25% chance in Kansas (up 5%), a 23% chance in South Carolina (up 5%) and a 20% chance in Alaska (up 6%).

Democrats are a more remote chance in Texas (13%) and Mississippi (11%).

To sum up the Senate: Democrats will probably lose Alabama and gain Colorado, Arizona, North Carolina and Maine. That results in a Senate split 50-50. If Democrats also gain Iowa and the Georgia special seat, where they are narrowly ahead, that gets them to 52-48, a solid enough majority to enable Biden to govern effectively.

So Democrats would be feeling good about the Senate – but it is not a done deal and there is little room for error. 

*Assuming Biden wins all electoral votes in Maine and one electoral vote in Nebraska, which do not award all their electoral votes to the statewide winner.