The United States presidential election will be held next Tuesday, with results coming in Wednesday AEDT. In analyst Nate Silver’s aggregate of national polls, Democrat Kamala Harris leads Republican Donald Trump by 48.6–47.5, a slight gain for Trump since Monday, when Harris led by 48.6–47.4. Harris’ national lead peaked on October 2, when she led by 49.4–45.9.

The US president isn’t elected by the national popular vote, but by the Electoral College, in which each state receives electoral votes equal to its federal House seats (population based) and senators (always two). Almost all states award their electoral votes as winner-takes-all, and it takes 270 electoral votes to win (out of 538 total).

Relative to the national popular vote, the Electoral College is biased to Trump, with Harris needing at least a two-point popular vote win to be the narrow Electoral College favourite in Silver’s model.

In Silver’s averages, Trump has a 0.6-point lead in Pennsylvania (19 electoral votes), up from 0.3 on Monday. Trump has slightly larger leads of one to two points in North Carolina (16), Georgia (16) and Arizona (11). Harris is narrowly ahead by 0.1 point in Nevada (six) and about one point ahead in Michigan (15) and Wisconsin (ten).

If current polls are exactly right, Trump wins the Electoral College by 281–257. Not making Pennsylvania’s popular governor Josh Shapiro her running mate could be Harris’ biggest mistake.

In Silver’s model, Trump has a 54% chance to win the Electoral College, slightly higher than 53% on Monday. There’s a 29% chance that Harris wins the popular vote but loses the Electoral College. The FiveThirtyEight forecast gives Trump a 51% win probability.

Without a major event, there isn’t likely to be much change in the polls before the election, but a polling error where one candidate overperforms their polls could still occur. Silver’s model gives Trump a 22% probability of sweeping the seven swing states and Harris a 12.5% probability.

I wrote about the US election for The Poll Bludger yesterday, and also covered three Canadian provincial elections and Japan’s conservative LDP, which has governed almost continuously since 1955, losing its majority at an election last Sunday.

Biden a drag on Harris and favourability ratings

Joe Biden remains unpopular with a net -16.5 approval in the FiveThirtyEight national aggregate, with 55.8% disapproving and 39.3% approving. As Harris is the incumbent party’s candidate, an unpopular president is a key reason for Trump’s edge.

Biden’s remarks on Tuesday, in which he seemed to call Trump supporters “garbage”, resembled Hillary Clinton’s “basket of deplorables” in the 2016 presidential campaign. This won’t help Harris.

Biden is almost 82, Trump is 78 and Harris is 60. Trump’s age should be a factor in this election that favours Harris, but Silver said on October 19 that Democrats spent so much time defending Biden before he withdrew on July 21 that it’s now difficult for them to attack Trump’s age without seeming hypocritical.

Harris’ net favourability in the FiveThirtyEight national aggregate is -1.5, with 47.8% unfavourable and 46.3% favourable. Her net favourability peaked at +1 in late September. Trump’s net favourability is -8.5 with 52.1% unfavourable and 43.6% favourable; his ratings have improved a little in the last two weeks.

While Harris is more likeable than Trump, that’s not reflected in head to head polls. Silver said on October 23 that Trump’s campaign is promoting him as not-nice, but on your side, and as someone who will get things done. They argue Harris’ campaign lacks clear policies.

Harris’ running mate Tim Walz is at +2.6 net favourable, while Trump’s running mate JD Vance is at -6.9 net favourable. In the past few weeks, Vance’s ratings have improved slightly while Walz’s have dropped back.

Congressional elections

I last wrote about the elections for the House of Representatives and Senate that will be held concurrently with the presidential election on October 14. The House has 435 single-member seats that are apportioned to states on a population basis, while there are two senators for each of the 50 states.

The House only has a two-year term, so the last House election was at the 2022 midterm elections, when Republicans won the House by 222–213 over Democrats. The FiveThirtyEight aggregate of polls of the national House race gives Democrats a 46.2–46.1 lead over Republicans, a drop for Democrats from a 47.1–45.9 Democratic lead on October 14.

Senators have six-year terms, with one-third up for election every two years. Democrats and aligned independents currently have a 51–49 Senate majority, but they are defending 23 of the 33 regular seats up, including seats in three states Trump won easily in both 2016 and 2020: West Virginia, Montana and Ohio.

West Virginia is a certain Republican gain after the retirement of former Democratic (now independent) Senator Joe Manchin at this election. Republicans have taken a 5.4-point lead in Montana in the FiveThirtyEight poll aggregate, while Democrats are just 1.6 points ahead in Ohio.

Republicans are being challenged by independent Dan Osborn in Nebraska, and he trails Republican Deb Fischer by 2.3 points. Democrats did not contest to avoid splitting the vote. In Democratic-held Wisconsin, Democrats lead by 2.1 points, while other incumbents are ahead by at least three points.

If Republicans gain West Virginia and Montana, but lose Nebraska to Osborn, and no other seats change hands, Republicans would have a 50–49 lead in the Senate. If Harris wins the presidency, Osborn would be the decisive vote as a Senate tie can be broken by the vice president, who would be Walz. This is the rosiest plausible scenario for Democrats.

The FiveThirtyEight congressional forecasts give Republicans a 53% chance of retaining control of the House, so it’s effectively a toss-up like the presidency. But Republicans have an 89% chance to gain control of the Senate.