For years, the dominant belief in both parties has been that Democrats need to run up a big lead in the national presidential popular vote to win an Electoral College majority. But in the dead-heat election of 2024, that may no longer be true. The distinctive dynamics of the 2024 campaign could allow Kamala Harris to eke out an Electoral College win even if Donald Trump runs better in the national popular vote this time than during his previous two campaigns.

The belief that Democrats need a big popular-vote win to prevail in the electoral vote hardened in the course of those two previous Trump campaigns. In 2020, Joe Biden beat Trump by a resounding 4.5 percentage points in the popular vote but still only squeezed past him by relatively small margins in the three Rust Belt battlegrounds of Michigan, Pennsylvania, and Wisconsin that decided the race. In 2016, Hillary Clinton beat Trump by two points in the national popular vote but narrowly lost those same three states, and with them the presidency.

That history has weighed heavily on Democrats as a procession of recent polls has shown Trump shrinking or even erasing Harris’s national lead. But the pattern of differences among white, Black, and Latino voters found in most of those national surveys show how Harris could still potentially capture the 270 Electoral College votes needed for victory—even if she wins the nationwide popular vote by much less than Biden did in 2020, and possibly by only about the same margin that Clinton got in 2016.

The principal reason is that these recent polls show Trump making most of his gains in national support by performing better among Black and, especially, Latino voters than he did in either of those previous elections. Even the most favorable surveys for Trump consistently find Harris polling very close to Biden’s level of support in 2020 among white voters, which had improved over Clinton’s performance with that group by several points. In other words, Harris will likely rely a bit more on white voters than her party’s past two nominees did.

That subtle shift is the crucial distinction from the earlier contests. It could allow Harris to scrape a win by sweeping the predominantly white, former “Blue Wall” battlegrounds of Michigan, Pennsylvania, and Wisconsin, even if Trump improves over his prior popular-vote results by gaining among Black and Latino voters (and Black and Latino men in particular).

[Read: Elon Musk wants you to think this election’s being stolen]

In each of his previous two races, Trump benefited because the decisive states leaned more Republican than the nation overall. In both 2016 and 2020, Wisconsin was the tipping-point state that provided the 270th Electoral College vote for the winner—first for Trump, then for Biden. In 2016, Trump ran about three percentage points better in Wisconsin than he did nationally; in 2020, he ran nearly four points better in Wisconsin than he did nationally, according to the University of Virginia Center for Politics.

The fact that Trump each time performed much better in the tipping-point state than he did in the national popular vote is central to the assumption that Democrats can’t win the Electoral College without a popular-vote majority. But as the Center for Politics research demonstrates, that hasn’t always been true.

The tipping-point states in the three presidential elections preceding 2016—Ohio in 2004 and Colorado in 2008 and 2012—each voted slightly more Democratic than the national popular vote. And in none of those elections was the disjunction between the tipping-point-state result and the national popular vote nearly as big as it was in 2016 or 2020. In fact, the gap between the national popular vote and the tipping-point state in Trump’s two races was considerably wider than in any election since 1948, the Center found.

Polling in the past few weeks, however, has indicated that this gap has shrunk to virtually nothing. Trump and Harris remain locked in a virtual tie both nationally and in the swing states. With polls that closely matched, none of the swing states appears entirely out of reach for either candidate.

Still, professionals on both sides with whom I’ve spoken in recent days see a clear hierarchy to the states. Both camps give Harris her best chance for overall victory by winning in Michigan, Pennsylvania, and Wisconsin; Trump is considered stronger across the Sun Belt in North Carolina, Arizona, Georgia, and Nevada (ranked from most to least promising for him).

That separation reflects the race’s unexpected racial dynamics. If Trump’s polling gains among voters of color bear out in practice, that would benefit him the most in the Sun Belt battlegrounds. There, minority voters are such a large share of the electorate that even a small shift in their preferences—toward Trump—would greatly diminish Democrats’ chances.

Whatever happens in the Sun Belt, though, if Harris sweeps the Rust Belt big three, she would reach exactly the 270 Electoral College votes needed to win (so long as she held all of the other states that Biden carried by about three percentage points or more, which is very likely). All three of those major industrial states are much less diverse than the nation as a whole: In 2020, white people cast about four-fifths of the vote in Michigan and Pennsylvania, and roughly nine-tenths of it in Wisconsin, according to census figures.

“One of the potential outcomes here is that at the end of the day, Trump will have gained with Blacks and Latinos and it may not have decided the Electoral College, if we don’t need [the Sun Belt states] to win,” Paul Maslin, a Democratic pollster with long experience in Wisconsin, told me.

Obviously, Harris has no guarantee that she could survive a smaller national popular-vote margin than Biden: The polls showing national gains for Trump could be capturing a uniform uptick in his support that would deliver slim victories across most—and possibly all—of the seven decisive states. Even the most optimistic Democrats see marginal wins in the battlegrounds as probably Harris’s best-case scenario. But the prospect that she could hold the former Blue Wall states even while slipping nationally challenges the conventional wisdom that Democrats must amass a significant lead in the national popular vote to secure enough states to win the electoral vote.

“The Blue Wall states are the likeliest tipping point for either candidate,” Kyle Kondik, the managing editor of the Sabato’s Crystal Ball newsletter published by the Center on Politics, told me. “If the country moves two to three points to the right but those states only move a point or less, that’s where you start to get the tipping point looking pretty close to the popular vote.”

The Democratic strategist Mike Podhorzer, a former political director at the AFL-CIO, also believes that Harris could win the Electoral College with a smaller popular-vote advantage than most analysts have previously assumed. But he says the demographic characteristics of the swing states aren’t the primary cause of this possibility. Rather, the key factor is that those states are experiencing the campaign in an immersive way that other states are not thanks to huge advertising spends, organizing efforts, and candidate appearances.

That disparity, he says, increases the odds that the battleground states can move in a different direction from the many states less exposed to such campaigning. Both Podhorzer and Kondik note that the 2022 midterm elections supported the general thesis: Although broad dissatisfaction with Biden allowed Republicans to win the national popular vote in House elections, Democrats ran much better in statewide contests across the most heavily contested battlegrounds, especially in Michigan, Pennsylvania, Wisconsin, and Arizona.

“It is really the difference between how well you are doing outside the battlegrounds and inside the battlegrounds,” Podhorzer told me. Inside the battlegrounds, he pointed out, voters have for years now been exposed at blast-force volume to each party’s arguments on all the major issues. “The cumulative effect of it is that they have an awareness of what is at stake, a different worldview, than people living outside those states,” he said.

The analogue to 2022 this year would be whether general disappointment in Biden’s economic record increases Trump’s popular-vote total in less-contested blue and red states alike, but Harris holds on to enough of the battlegrounds where voters are hearing the full dimensions of each side’s case against the other.

[Read: How the Trump resistance gave up]

The same national polls that show Trump gaining among voters of color this year do not show much, if any, improvement for him compared with his 2020 performance among white voters. The latest aggregation of high-quality national public polls published by Adam Carlson, a former Democratic pollster, found that Harris is almost entirely preserving Biden’s gains among white voters; that means Harris is also exceeding Clinton’s showing with them from 2016.

The comparison with Clinton is instructive. Among voters of color, Clinton ran better in 2016 than either Biden in 2020 or how Harris is polling now. But Clinton lagged about three to four points below both of them among white voters. If Harris wins the popular vote by only about the same margin as Clinton, but more of Harris’s lead relies on support from white voters, the vice president’s coalition would be better suited to win the Rust Belt battlegrounds. In that scenario, Harris would assemble what political scientists call a more electorally “efficient” coalition than Clinton’s.

Biden’s margins of victory in the former Blue Wall states were so slim that Harris can’t afford much erosion with voters of color even there. But two factors may mitigate that danger for her. One is that in the Rust Belt states, most voters of color are not Latino but Black, and Democrats feel more confident that they can minimize losses among the latter than among the former.

The other key factor is a subtle change in those states’ white populations. Calculations from the latest census data provided to me by William Frey, a demographer at the nonpartisan Brookings Metro think tank, found that since 2020, white voters without a college degree—the demographic group in which Trump performs best—have declined as a share of eligible voters by about three percentage points in both Michigan and Wisconsin, and by about 1.5 points in Pennsylvania. In Michigan and Wisconsin, college-educated white voters, who now tilt mostly toward Harris, largely made up the difference; in Pennsylvania, the share of minority voters grew. In a typical election, these slight shifts in the electorate’s composition probably would not matter, but they could in a contest as close as this one.

“There is still room to grow in the suburbs [across the region], and two things are going to contribute to that growth: January 6 and the Dobbs decision,” Mike Mikus, a Pittsburgh-based Democratic consultant, told me, referring to the insurrection at the Capitol in 2021 and the 2022 Supreme Court ruling that overturned the constitutional right to abortion. The racist slurs against Puerto Rico at Trump’s Madison Square Garden rally last weekend could also cost him with Pennsylvania’s substantial Puerto Rican population.

Sweeping Michigan, Pennsylvania, and Wisconsin with a smaller national-popular-vote lead than Biden’s is nonetheless a high-wire assignment for Harris. A significant concern for Democratic strategists is whether the party has plausibly declined since 2020 only among voters of color, without suffering material losses among white voters as well.

One strategist with access to a wide array of party polls, who asked for anonymity to discuss that private research, told me that although many Democrats are optimistic that surveys overestimate Trump’s strength among Black voters, a risk also exists that polls underestimate Trump’s strength with white voters (something that has happened before). That risk will rise if Trump turns out unexpectedly large numbers of the blue-collar white voters who compose the largest share of infrequent voters in the Rust Belt battlegrounds.

However, the Republican pollster Whit Ayres told me that he is seeing the same divergence between slipping non-white support and steady white backing for Harris in his surveys—and he sees good reasons for that pattern potentially persisting through Election Day. “The Hispanic and African American weakness [for Harris] is a function of a memory of the Trump economy being better for people who live paycheck to paycheck than the Biden-Harris economy,” Ayres said. “On the other hand, there are far more white voters who will be voting based on abortion and the future of democracy. There’s a certain rationale behind those numbers, because they are making decisions based on different issues.”

Democrats generally believe that they maintain a fragile edge in Michigan and Wisconsin, partly because many public polls show Harris slightly ahead, but even more because their party has built a better turnout operation than the GOP in those states. Pennsylvania looks like the toughest of the three for Harris and, in the eyes of many strategists in both parties, the state most likely to decide this breathtakingly close race.

“Looking statewide, I’ve always thought from the time she got in that Harris would do better in the suburbs and the cities than Biden, and Trump would do better in a lot of these redder counties, and the million-dollar question is what number is bigger and how much bigger,” Mikus, the Pittsburgh-based consultant, told me.

Biden carried the Keystone state by only 1.2 percentage points while winning the national popular vote by nearly 4.5 points. Whether Trump wins a second term to execute his dark vision of “retribution” against “the enemy from within” may be determined by whether Harris can hold Pennsylvania while winning the national popular vote by much less, if at all. It would be a fitting conclusion to this bitter campaign if the state that decides the future shape of American democracy is the same one where the nation’s Constitution was written 237 years ago.