Kamala Harris only has one serious route to the White House. It’s narrow

If the Democrat cannot win Pennsylvania, her chances of securing the White House collapse

Despite the jubilation among Democrats, the entry of Kamala Harris into the race for president has not tipped the electoral balance firmly in their favour. Our latest model shows that, in 59 per cent of our simulations, Harris loses to Donald Trump.
The reasons for this are simple. In replacing Biden, Harris removed the thorn in the Democrats’ side. There can be no claims of poor mental faculties or old age with her. Neck-and-neck in a race is fine, but without a clear strategy from the Democrats, Trump could still walk into the White House.
Our latest modelling shows the strategic way for Harris to win the presidency. This route runs through the closest state in the country, Pennsylvania. The Keystone State is really living up to its name – winning this state would drastically strengthen Harris’ position in the race.
The Democrat safe states mean that Harris enters the ring with around 226 electoral college votes – 44 short of the 270 she needs. With the seven remaining states, she might naively think that she has a whole host of possible routes to the White House. However, some are more sensible than others.
In all but two swing states – Michigan and Wisconsin – Trump leads Harris. If she wins those two states, she makes it to 251 and hands victory to the Republican. There are two ways for Harris to overcome this. The first is to win Michigan and Wisconsin and go on to win Pennsylvania – taking her to 270. The second is to take Michigan and Wisconsin, and then Nevada and North Carolina – bringing her to 273 electoral college votes.
But this latter route is potentially harder to achieve. According to our model, only about 2 per cent of her wins come as a result of losing Pennsylvania and winning the four states above, and this outcome occurs in less than 1 per cent of our simulations.
This route is difficult for a number of reasons. First, it relies on her winning more states; winning four states is less likely to happen than three. Second, while Harris trails Trump in Pennsylvania, she is currently more likely to win that state than North Carolina. Trying to win more of the states in which you are lagging behind does not make for a good electoral strategy.
So the most sensible route to the White House for Harris is via Pennsylvania. Trump is predicted to win this state by about 55,000 votes. Over 82 per cent of Harris’ simulated wins involve winning Pennsylvania, Wisconsin and Michigan. But Pennsylvania is key – just 10 per cent of her wins come about without securing the state.
So Harris’ best route to the White House runs through the Keystone State and the Great Lakes. If she could guarantee winning all three states, then the probability of her winning the electoral college jumps by over 30 points. In this scenario, Harris wins in four out of every five simulations.
How she persuades Pennsylvanian voters is a complex question. But Jim Carville’s words still ring true today: “It’s the economy, stupid”. In a recent poll, the economy was the top issue for Pennsylvanians, ahead of immigration by some distance.
The salience of this issue makes it the most important area for the Harris campaign to focus on. Unfortunately, polling from late September shows that only 46 per cent of Pennsylvanians think Harris would handle the economy better – 52 per cent think Trump would be better suited.
The picture looks bleak. Nevertheless, new research from the independent Committee for a Responsible Federal Budget shows that, while Harris’ plans would add around $3.5 trillion to the federal debt, Trump’s plans would add a whopping $7.5 trillion. While the deficit is not a major flashpoint in American politics, focusing on the profligacy of the Trump tax plans may erode the confidence the Pennsylvanian public has in Trump. It may also pull some undecided and floating Trump voters into the Harris camp.
There are further chinks in Trump’s economic armour. Pennsylvania is an industrial state and the Trump administration’s relatively poor record in this area could be exploited by Democrats. By the end of the Trump administration, there were 178,000 fewer manufacturing jobs and nearly 13,000 fewer coal mining jobs. Much of this can be attributed to the pandemic but, in a race like Pennsylvania, moving the narrative could give Harris the few tens of thousands of votes she needs.
Trump’s proposed tariffs are also an area Harris’ team could exploit in the state. While intended to help US manufacturing, tariffs can backfire – both for industries that rely on imports for their operations and for consumers, potentially reducing other tax revenues.
The case is clear. Harris’ best option is to go for it in Michigan, Wisconsin and Pennsylvania. And if she focuses on the economy, Trump’s profligacy and spins his poor performance on industrial jobs, she could start to dominate on the top issue for Pennsylvanians – the economy.
Callum Hunter is a senior data scientist at JL Partners