Both campaigns agreed the presidential election was unprecedented with only an extremely narrow slice of the electorate up for grabs and the Democrats having to retool strategy and organization for a new candidate in the final stretch. And the thing that may have made the biggest difference was how and where you talked to undecided voters.

Senior staff from the Harris and Trump campaigns gathered at Harvard Kennedy School Friday to explain their thinking at critical junctures during the 2024 election. The postmortem, organized by the Institute of Politics, has been held after every presidential election since 1972.

Jen O’Malley Dillon, who had managed President Joe Biden’s 2020 and 2024 campaigns before taking the helm of Vice President Kamala Harris’ campaign after Biden dropped out in July, acknowledged the considerable difficulty they faced trying to shift a political operation built for one candidate to another with a little more than three months left in the race.

“But when the call came and the president said he was getting out, we really did flip the whole thing without knowing exactly how to do it,” she said. “And then the vice president was so strong out of the gate that I think it made momentum a little bit easier for us to pick up on and gave us a little bit of space to figure out the stuff we hadn’t worked out yet.”

The Harris team said they knew from the start that they would be facing significant headwinds because the economy was emerging as a top issue, and voters felt the Biden-Harris administration had not done enough to address the inflation rate.

Beyond that, the Harris campaign leaders walked through other challenges they faced.

They pushed back on the accusations by pundits that they took certain demographic groups, like Black and Latino men, and younger voters, for granted, assuming that Harris’ race and gender would override economic or national security concerns.

“We weren’t running this campaign as an identity politics campaign,” said Quentin Fulks, principal deputy campaign manager for Harris. “We came out of the gate talking to everyone. If you think the economy sucks, it doesn’t get better if there’s a Black candidate.”

At the same time, Fulks said, “It didn’t help that the Trump campaign was obviously targeting these voters and making them feel … whether it be through [an anti-] trans ad, ‘She’s for they/them and Trump is for you,’ they were making her seem as if she was out of touch and out of line with their issues.”

Where the Harris team saw the biggest shift in support was among third-party voters, particularly those who had been dissatisfied with both Biden and Trump. Once Harris got in the race, however, “those voters snapped back very quickly” to the Democratic side, said Harris pollster Molly Murphy. Surprisingly, older voters, a group that Biden had always done well with, ended up being much more supportive of Harris than the campaign expected.

Responding to a common complaint from progressives that Harris’ elevation to the top of the ticket without a primary process was undemocratic, Fulks noted there were just 107 days left after Biden dropped out in which to identify a new candidate, unify the party, and launch an entirely new campaign before Election Day.

To hold an open primary and bypass Harris, Biden’s preferred choice, would have risked alienating Black women, a key Democratic Party voting bloc, and meant fielding a lesser-known candidate with no infrastructure, he said.

“I hear your concern, and I’m not saying that … open primaries are not important, but I also think [the campaign was] such an anomaly [that] it would have almost been virtually impossible to have an open primary of any success that would have put the Democratic Party in a position to be able to defeat Donald Trump,” he said.

The Trump team said that early on one of their biggest challenges involved negative impressions of Project 2025, a collection of conservative policy proposals pushed by the Heritage Foundation and other conservative groups.

Voter concern started to gain traction while Biden was still in the race, especially on TikTok, and it caught the Trump team by surprise. That worry grew to alarm after seeing persuadable voters start to move in response to reports about it and Trump blowing up in anger over news stories tying the document directly back to him, they said.

“Obviously, we recognized that it was an issue, and we needed to kill it quickly,” said Chris LaCivita, co-manager of the Trump campaign.

In fact, Project 2025 was one issue where Democrats had a leg up on the Trump team, but by the time the Harris campaign began to focus on it, noted Tony Fabrizio, a veteran Republican pollster, the race had evolved, and that earlier stickiness and momentum was very hard for Harris to reclaim.

Both sides agreed that communication strategies may have made the biggest difference in 2024. The Republicans proved more effective at crafting and amplifying messages that resonated with 2024’s undecided voters. With so few up for grabs this election, finding and persuading those folks was critical.

Seeing that these voters were part of a larger, growing cohort of Americans who had unplugged from network and cable television, the Trump campaign invested heavily in targeting “streamers” (those who exclusively used streaming services), fans of internet-only programs, and listeners of entertainment podcasts, Fabrizio said.

And it’s why candidate Trump did unconventional things like attend mixed martial arts fights to show those voters he understood them and was reaching out, LaCivita added.

The media asymmetry turned out to be a decisive advantage for Republicans this year, but maybe not for much longer, Fabrizio said.

“Republicans were always more distrustful of what we’ll call the mainstream media than Democrats or independents. And so, what happened is, when the technology became available for alternative sources of information, Republicans were the first ones to flock to it because they weren’t happy. It’s the reason why Fox [News]exploded, it’s the reason why so many online sites are right-of-center sites,” he said. 

There are signs the left is also becoming disillusioned with mainstream media after controversies over endorsements at The Washington Post and The LA Times led to the cancellation of more than 250,000 subscriptions, and plummeting ratings at CNN and MSNBC post-election. Younger voters now turn increasingly to TikTok and other online platforms for news, an arena in which the Trump campaign conceded that the Harris team outplayed them. Most importantly, a recent Gallup poll shows only 31 percent of Americans still trust the media.

“That means there’s a chunk of Democrats that don’t trust the media anymore,” Fabrizio said. “As that distrust grows across the partisan spectrum, you’re going to see a greater proliferation of news sources and information sources, both on the right and the left. It’s just going to take a little bit more time for the left to get to where the right has been for several years about the news media.”