Election 2024 updates: With Arizona, Trump sweeps all 7 swing states

In the months leading up to Biden's decision not to seek reelection, pundits speculated about the advantages and drawbacks of an open convention or a "mini-primary." to choose a potential replacement. But when Biden eventually did make that decision, that's not what happened. Instead, the party coalesced around Harris very quickly. She won endorsements from moderates like the New Democrats Coalition as well as congressional progressives, from party and movement figures like former Planned Parenthood president Cecile Richards and former President Barack Obama and former First Lady Michelle Obama, and, crucially, from potential competitors like Michigan Gov. Gretchen Whitmer and California Gov. Gavin Newsom.

One thing about these "invisible" party primaries, whether they happen in a hurry as they did this year, or over the course of a longer campaign as they normally do, is that we often don't know exactly how it happened. The legacy of Hillary Clinton's loss to Trump in 2016 may have left Democrats especially wary of potential internal disagreement. It is notable that congressional progressive leaders Sen. Bernie Sanders (Clinton's main challenger back in 2016) and Rep. Alexandria Ocasio-Cortez were among Biden's strongest defenders during the final weeks, when calls for him to drop out intensified. Intentionally or not, this may have held off a progressive challenge that could have complicated Harris'Harris's path.
As Monica noted earlier, an area where it's unclear whether Harris has successfully consolidated the party is the vocal faction that opposes the Biden-Harris administration's policy toward Israel and the war in Gaza. There were pro-Palestinian protests at the DNC in Chicago, and complaints that a speaker representing the pro-Palestinian movement was not featured. Questions have remained about whether the issue might hurt Harris particularly in Michigan, where the Uncommitted National Movement showed some strength in protesting Biden's nomination during the primaries. Recently a group of Muslim leaders endorsed Harris in hopes of preventing that outcome. What remains to be seen is whether the election will be close enough that these cracks in the Democratic coalition prove decisive.

This summer saw major political events occur one after the other (or occasionally at the same time), with unprecedented news breaking seemingly almost every week about the presidential race. Between the assassination attempt on Trump to Biden's disastrous debate performance that ultimately led him to drop out of the race, it's fair to say that this summer was one of the most volatile periods in recent presidential campaign history.

But the unpredictability of news events didn't necessarily translate to huge swings in the polls. In fact, we've had one of the steadiest presidential races in modern history, according to the polls. Before Biden dropped out, neither candidate's standing in our old national polling average changed by more than 3 percentage points over a span of almost five months. The story is similar in our new average that we launched after Harris took the reins as the Democratic nominee. Compare that to the 2020 campaign, where Biden maintained a consistent lead, but the polling average changed more dramatically throughout the year, with a difference of over 7 points between the largest and smallest margins.

There's been a variety of theories floated about why this year's polling looks more stable than past cycles. The shift may be a result of pollsters making methodological choices that increase the stability of the polls, or it could just be a reflection of a stubbornly polarized electorate in which relatively few voters are actually up for grabs from either campaign. Either way, 2024 has emerged as one of the most stable presidential elections in the modern polling era.

Throughout this year's primaries, the Israel-Hamas war dogged Biden's reelection campaign, and the issue has inspired an intra-party conflict that Harris inherited when she advanced to the top of the ticket. The Uncommitted National Movement, a group founded by Arab and Palestinian Americans and joined by progressives, made a name for itself protesting to prod the Biden administration and Harris campaign to take a firmer stance against the Israeli military's actions against Hamas and to enact an arms embargo until Israel commits to better protections for civilians in Gaza. If the conflict siphons away support from pro-Palestinian voters who would otherwise support Harris, it's an issue that could help swing the election for Harris or Trump in a tight race.

Harris has not supported an arms embargo, but she has called for a ceasefire and endorsed a two-state solution. "President Biden and I are working to end this war, such that … Palestinian people can realize their right to dignity, security, freedom and self determination," she said during her acceptance speech at the Democratic National Convention in August.

Meanwhile, Trump has bragged in the past about being the most pro-Israel president in history and has doubled down on support for Israel in recent weeks. After the death of Hamas's leader, Yahya Sinwar, Trump praised Israeli Prime Minister Benjamin Netanyahu and said Biden was "trying to hold Netanyahu.

Americans still generally support Israel, but as the war has continued and Gaza's civilian death toll has mounted — it's now estimated to be more than 41,000 people — more have come to see Israel's response to the Hamas Oct. 7 terrorist attacks as too harsh and have become more sympathetic with Palestinians. Fewer support increased military aid to Israel and more support increased humanitarian aid to Gaza than did at the beginning of the war. And while Trump has had an advantage when it comes to who voters say they trust more to handle the conflict in the region, more than a third of Americans in a YouGov/The Economist poll from late September said they weren't sure whether Trump or Harris had been too supportive or not supportive enough of Israel, meaning the candidates might have had room to persuade voters over the last month.

For its part, the Uncommitted National Movement has declined to endorse Harris, but also communicated that they think another Trump presidency would be even worse than the status quo and urged against third-party votes, particularly in swing states. Still, the current administration's handling of the Israel-Hamas War has cost Harris some support, especially in Michigan, which has one of the largest Arab-American populations in the country. Vermont Sen. Bernie Sanders, a national progressive leader and critic of the war, pleaded on social media last week for those worried about Palestinian rights to vote for Harris, emphasizing that she would be more sympathetic to their interests than Trump. Tonight's results could tell us something about whether that argument is enough to move voters back toward Harris.

In the final weeks of the campaign season, voters faced a flood of campaign ads highlighting competitive congressional races, big referendums and, of course, the presidential race. According to Wesleyan Media Project's final pre-election analysis of campaign ads, nearly $4.5 billion was spent in advertising for federal and gubernatorial races this election cycle on TV and radio alone.

On the 538 Politics podcast last month, we tried to understand more about the content and volume of these ads and make sense of which presidential candidate had an advertising edge over the other. This cycle, Harris outspent Trump on digital ads, dedicating nearly $215 million to Meta and Google platforms compared to Trump's $49 million. This gap in spending echoes the 2020 election, when Biden also led in digital ad spending.

Targeting the seven battleground states, each candidate crafted distinct messages. According to the Wesleyan Media Project report, over 70% of Harris' ads focused on women's rights and abortion, whereas over 97% of Trump's ads focused on taxes.

We also talked about the fact that, in recent weeks, both candidates aired very few positive ads, primarily releasing attack and contrast ads. The effect advertisements have on election results is argued by political scientists, but in a race as close as this one, researchers suggest the tone of the ads could tip the results.

Listen to the full podcast for more insight into how tone, issue-focused ads, spending gaps and ad frequency impacted this election cycle.