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

We’ve talked a lot about how polling error is a fact of life in elections, but polling bias also tends to happen. Now, when we say bias, we don’t mean intentional efforts to put out polls that favor the preferred party of the pollster and/or sponsoring organization. Instead, polling bias indicates to what extent pollsters as a whole over- or under-estimated one party’s actual performance in the election.

For instance, we know that pollsters underestimated Trump’s position in the 2020 presidential election, to the tune of an average bias of about 4 points more Democratic than the real result. In 2016, the bias was similarly around D+3. So we’ve had two straight presidential cycles in which the polls have exaggerated the Democrats’ standing in the polls, which naturally makes people suspicious that we could once again see pollsters undershoot Trump’s actual vote share in 2024.

However, one only has to look a little farther back to see that polling bias does not consistently favor one party or the other. In 2012, pollsters undershot Barack Obama’s result in the presidential race by an average of about 2.5 points. And all told, the average bias in presidential elections dating back to 2000 is about a point more Democratic than the actual outcome. The broader point is, it’s nigh impossible to predict which direction polling bias will go ahead of the election. Pollsters are constantly working to try to overcome the challenges facing their industry, so expecting the past to be prologue when it comes to error and/or bias is a fool’s game.

This campaign season, both Harris and Trump have been criss-crossing the country, holding raucous rallies, moonlighting at local businesses and even stopping by a football game. Despite early concerns from some Democrats that Harris wasn’t holding enough campaign events, both candidates have been campaigning hard in the final stretch, averaging more than one event per day. According to tracking by VoteHub, Trump has held 49 campaign events since Oct. 1, while Harris has held 45.

In the seven main swing states, though, Harris and Trump have actually held the same number of events (42). Harris has been focusing especially hard on Michigan, while Trump has held the most events in North Carolina. Neither candidate has spent too much time in Nevada or Arizona (perhaps they’re just too far out of the way to be worth it).

Trump has also held seven events in non-swing states, such as his rally at Madison Square Garden in New York City. While that may seem like poor strategy at first glance, it actually probably doesn’t matter that much: Political science research shows that campaign events don’t actually boost a candidate’s vote share in the places they visit. The reality is, the vast majority of people who attend these events are already supporting the candidate, and any boost the candidate gets from media coverage of the event is fleeting.

Portland isn't the only city where homelessness will be a key issue in the mayoral race. A competitive race in San Francisco, focused on crime and homelessness, is also shaping up to potentially change local dynamics in the city. Like Portland's mayoral election, the race will be conducted using ranked-choice voting. And for the first time this year, the San Francisco mayoral election will coincide with the presidential election, after voters passed a ballot referendum in 2022>) to move the date of the mayoral race — a change that gave current Mayor London Breed an extra year in office.

Unfortunately for Breed, that extra year doesn't seem to have helped her reputation in the city. According to an early September poll by Emerson College/KRON-TV, only 27% of San Francisco voters approved of the job Breed was doing as mayor, while 51% disapproved, numbers that are in line with other surveys of the city.

Breed first became acting mayor in 2017, after the death of Mayor Ed Lee, and was elected to a full term in 2019. She initially took more progressive stances on issues like police funding and homelessness, but she's since reversed course. Over the last few years, Breed has boosted funding to law enforcement, and in the wake of a recent Supreme Court decision allowing cities to arrest or fine people sleeping on the streets, she encouraged officials to start issuing citations to homeless people and offer them free bus tickets out of town, rather than housing them.

And while overall crime in the city is down significantly even from pre-pandemic levels, Breed has also struggled to manage a looming budget deficit and a significant number of overdose deaths in the city.

As a result, the incumbent is facing some tough competition today, with a total of 11 candidates appearing on the ballot. Her main competitor, based on polls of the race, is Daniel Lurie, a political outsider who is an heir to the Levi Strauss fortune and founder of a local nonprofit organization that has worked on many of the key issues in the race — homelessness, criminal justice and poverty — a biography he's leveraged on the campaign trail. Board of Supervisors President Aaron Peskin is running slightly behind them, though not far enough that he's out of contention.

The latest poll from Sextant Strategies for the San Francisco Chronicle shows Breed winning the largest share of first-round votes, but losing out to Lurie by 12 points in the final round of ranked-choice voting. Other polls released by the Peskin and Lurie campaigns have shown a similar picture, with Breed doing well in the first round, but trailing when voters' second and third choices are tallied.

Polling and anecdotal evidence ahead of this year's election suggests that Democrats' longtime advantage with Latino voters is continuing to shrink, which could create a massive vulnerability for Harris and congressional Democrats in pivotal swing states.

These comments may not turn off conservative Latinos, however. Among other factors, how these voters align politically varies based on where they live, to what extent they prioritize their American identity over their ethnic identity and whether they went to college. And 538's own reporting suggests that Latino voters might be more prone to Republican candidates' messaging on race specifically. For example, many Latinos want stricter immigration reform more in-line with Republican's messaging. Some polling and research also shows that evangelical Latino voters buy into American nationalism and are turned off by identity politics, so they could be more receptive to the idea that the Democratic Party is out of step with their views.

A pronounced rightward shift this year wouldn't only hurt Harris, however. It could also affect Senate races in states with large Latino populations, particularly Arizona and Nevada. In both states, polling suggests that the Democratic candidates enjoy a comfortable lead over Republicans. Still, Harris and Trump are essentially neck-and-neck in both states, and a close margin at the top of the ticket could drag down Democratic Senate candidates. In Texas, too, Republicans have made inroads with Latino voters, especially those who live in the 28 counties bordering the Texas-Mexico border. A shift toward Republicans among those voters could be bad news for Rep. Colin Allred, a Democrat who polls show is within single digits of ousting Senator Ted Cruz.

In any case, both Harris and Trump continued to make a play for Latinos in the lead-up to today. And given the size of this electorate (Latinos make up about 15% of the eligible voting population), how this group votes this year could ultimately decide the eventual outcome of the 2024 race.