Certainty is a beautiful thing. It is also to be mistrusted, especially in politics, and especially after the past three weeks in the presidential race, which have seen, among other things, the attempted assassination of Republican nominee Donald Trump and the abdication of presumptive Democratic nominee Joe Biden. So when I asked an ally of Kamala Harris the only question that really matters for the next three months—what does the sudden switch from Biden to Harris mean for the races in battleground states that will decide who wins the White House?—I was thrilled to hear the answer: “Nobody knows.”

We do know a few things, however. One is that Harris insiders don’t agree with the conventional wisdom that quickly emerged after she replaced Biden: that having a Black female nominee makes things easier in Sunbelt states like North Carolina and Georgia and more challenging in the crucial “blue wall” states of Wisconsin, Michigan, and Pennsylvania. Yes, maybe more white male voters turn out for Trump up north and more Black voters show up for Harris down South than they would if Biden were still the nominee. But Democratic candidates of all types still generally perform stronger in the blue wall states than in the Sunbelt. Early polling, though, has been encouraging pretty much across the board. Before Biden abruptly quit his reelection campaign on July 21, Trump was ahead and widening his polling lead in Pennsylvania, Arizona, Michigan, Georgia, and Nevada. The first series of surveys has shown Harris surpassing Biden’s support in the first four, plus Wisconsin.

Another knowable impact of the shift from Biden to Harris and the resulting boom in donations and volunteers is that she can stretch the electoral map. Biden’s strategy would have been to dig in and defend Wisconsin, Michigan, and Pennsylvania. Harris, however, will also compete hard in Arizona, Georgia, and perhaps Nevada, forcing Trump to do the same. Just two weeks ago, for instance, the former president appeared to be in solid shape in Georgia, where in 2020, Trump lost, infamously, by a mere 11,700 votes. Even LaTosha Brown, a cofounder of Black Voters Matter, headquartered in Atlanta, was discouraged. “I have a 25-year-old niece who called the president ‘Genocide Joe.’ We fought about that. I could not move her,” Brown says. “When Kamala took over, my niece called and said, ‘Where can I work?’” Her niece is not alone. According to vote.org, Georgia has seen the largest number of new voter registrations of any swing state since Biden stepped aside; nationally 162,000 people have signed up, and 82% of them are ages 18 to 34. An Emerson College poll of likely Georgia voters shows Harris trailing Trump within the margin of error, essentially erasing the advantage he held over Biden. Harris’s campaign recently added three offices in the state, bringing the total to 24, and on Tuesday, the candidate spoke at a large, exuberant rally in Atlanta featuring Megan Thee Stallion, the kind of event that would have been hard to imagine with Biden still atop the ticket.

The most optimistic Harris advisers believe she can expand the battleground map beyond the five consensus swing states. Dan Kanninen, the campaign’s battleground states director, told me back in March that he was bullish about North Carolina. However, one month ago, Trump led by eight points in 538’s polling average, and the state increasingly appeared to be a lost cause with Biden as the Democratic nominee. Barack Obama, in 2008, was the first Democratic presidential candidate in three decades to win North Carolina; strategist Cornell Belcher was part of Obama’s team back then, and he sees North Carolina as a state where Harris stands to gain the most ground. According to vote.org, North Carolina is a close second to Georgia in the number of new voter registrations since Biden’s announcement. “If you look at the Research Triangle [of Raleigh, Durham, and Chapel Hill] and her ability, I think, to add a couple points on with white women, primarily college-educated white women, and do a couple points better overall with college-educated voters,” Belcher says, “it’s the next state to flip.”

Yet his enthusiasm is tempered by a sense of reality mixed with déjà vu. In 2012, again working for Obama, Belcher made a case for the reelection campaign to seriously contest Mitt Romney in Georgia. “We did polling, and we could have put the state in play,” Belcher says. “But then the number crunchers determined that Georgia is really expensive. And it hasn’t gotten any cheaper. We can have these hypothetical conversations, but at some point, you run into the reality that, okay, North Carolina, Arizona, Georgia, Nevada, along with the traditional blue wall states—that’s a shitload of money and organizing.”

The Harris campaign, meanwhile, is trying to ride the wave of adrenaline, stockpiling cash and eager volunteers. The hard choices of where to deploy those resources will come up fast after the Democratic Convention, which is why her campaign’s leaders are focused on figuring out exactly which voters, in which parts of the battleground states, are most persuadable. What will be pivotal is not whether Harris energizes voters across broad categories, but whether she can boost Democratic turnout in specific places. Women in the suburbs of Philadelphia, northern Virginia, Detroit, and Phoenix, among other places, will probably be seeing and hearing a lot of ads highlighting Harris’s reproductive rights message and her theme of not allowing Republicans to take the country backward. In the home stretch, the bulk of Democratic time and money is likely to be poured into a map that looks remarkably similar to Biden’s, with significant investments in Wisconsin, Michigan, and Pennsylvania, where women and Black voters are seen as potentially decisive factors.

“She’s been like a defibrillator to the Democratic Party in this race,” says John Anzalone, a pollster whose clients included Biden in 2020 and Michigan governor Gretchen Whitmer today. “What she’s doing right now with young people, African Americans, Latinos, AAPIs, and college-educated women—it’s not just the base coming home. We were in danger of a universe of people not showing up. So it’s a double positive. But it’s still early.” There’s that admirable uncertainty again.