The systemic bias Kamala Harris must overcome in order to win
It is a common cliché in films: a character flicks through TV channels, seeing the same news story again and again. Pennsylvanians may feel as if their TV sets are mimicking the movies. Donald Trump and Kamala Harris are pouring money into the state. The two campaigns have splurged $189m on advertising there since March, according to the Pittsburgh Post-Gazette, compared with $105m in Michigan, the second-highest spend. The people of Pennsylvania can blame the bombardment on the electoral college, which means that the leader of 330m Americans is chosen by a few thousand voters in swing states.
This electoral system is an obstacle for Ms Harris, the Democratic nominee, as it was for Joe Biden and Hillary Clinton before her. Although our presidential forecast gives her a 71% chance of winning more votes than Mr Trump nationwide, she has only a 51% chance of winning the electoral college.
The electoral college is formed of electors from every state and the District of Columbia, roughly in proportion to their population. To get to the White House, a presidential candidate must win a majority—270—of the 538 electors. Aside from those in Maine and Nebraska, practically every elector votes for the winner of the popular vote in their state. This winner-takes-all system encourages candidates to focus on swing states, rather than on places where the outcome is pretty much assured.
This year, we estimate that Pennsylvania is the most likely state to be the “tipping-point”: it provides the 270th elector for Mr Trump or Ms Harris in 26% of forecast simulations. Pennsylvania is followed by Michigan, North Carolina and Wisconsin as the likeliest pivotal states. On average, the tipping-point states are whiter and poorer than the country as a whole. All this shapes candidates’ stances. Ms Harris has recanted her opposition to fracking, a big employer in Pennsylvania, for example. Both candidates have endorsed eliminating taxes on tips, which could play well with hospitality workers in Nevada, another potential tipping-point state.
Though Ms Harris leads in our tracker of national (pre-debate) polls by 2.5 percentage points, her margins are narrower in swing states. In Pennsylvania she leads by 0.7 points, according to FiveThirtyEight, an aggregator. By itself, this suggests the electoral college has a bias of 1.8 points—smaller than the 2.9 points in 2016 or 3.3 points in 2020.
But state opinion polls should be taken with a pinch of salt. In 2016 they indicated that Mrs Clinton was on course for victory. Although polls correctly suggested she had a small lead nationwide, they systematically overestimated her strength in swing states. Mr Trump won despite getting 2.9m fewer votes in total. Four years later, after months of favourable polling, Mr Biden won by the narrowest of margins in Wisconsin and Pennsylvania.
To hedge against this, our forecast combines polling with a “fundamentals” estimate of how states will lean, relative to the country, for example taking into account their tilt at the last election. The model believes Ms Harris will face an uphill struggle in the electoral college similar to Mr Biden: she would need a 2.1-point lead in the two-party popular vote to be the favourite to win the electoral college (see chart).
Alternative routes to 270 electoral-college votes may appear. But Pennsylvania’s nickname, the Keystone State, is looking apt. Regular programming will not resume for the time being. ■
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