CHICAGO ― Well, the party’s over.

The Democratic National Convention ― a four-day whirlwind of electric speeches, late-night bashes, policy panels and tens of thousands of attendees from all over the country feeling absolutely rejuvenated about the prospects of victory in November ― has come to an end.

Now comes the hard part as the hangover sets in: Democrats have to keep this off-the-charts momentum going for 72 more days and mobilize swarms of voters to turn out for Kamala Harris’ presidential campaign. If they can’t, given that this race is currently so tight that it could ultimately be decided by a handful of votes in certain precincts in swing states, there is a very real possibility that she will lose to former President Donald Trump.

Former first lady Michelle Obama got at this stark reality on Tuesday night, in what was easily the most effective speech of the convention: “Michelle Obama is asking you ― no, I’m telling y’all ― to do something.”

HuffPost was certainly a buzzkill at the convention, walking around asking elated delegates and attendees if they recognized, given current polling, that Harris could lose.

Rep. Melanie Stansbury (D-N.M.) acknowledged that the ongoing celebrations at the convention could be papering over the reality for people that the race remains extremely tight.

“I am very worried about that,” Stansbury said.

She drew some parallels to Hillary Clinton’s run for president in 2016, when Democrats headed to polls overly confident about victory only to see her lose to Trump. Buoyed by mistakenly rosy polling in key states and an over-reliance on data analytics, the Clinton campaign famously began advertising on TV in Texas, which was never really in contention. By contrast, during the general election, Clinton never campaigned in person in Wisconsin, a state where Trump bested her by a razor-thin margin.

Though the political landscape has changed dramatically since then ― millions of women marched in protest of Trump, thousands of women ran for office in 2018, social media has “become more democratized” and pollsters have updated their methods to account for changing voter habits ― Stansbury said there is still anxiety over a repeat because the stakes are so high and Democrats have only a couple of months to boost voter education and turnout.

“I think we’re all living with the PTSD of 2016,” she said. “Even if we know she‘s the most qualified candidate ever, if we don’t get out there and make sure people show up to vote, we can’t face the nightmare that would come. We can’t lose this election.”

Two attendees from Maryland, Kimberly Fernandez and Jarra Childs, summed up how they were feeling as the convention wound down.

“Motivated. Accomplished. Hopeful,” they said.

Fernandez, 41, acknowledged how tight the race is but said she feels “confident” that Harris will win. She said she’s ready to become active as a volunteer back home.

“I have a personal obligation now to keep it going. It’s not all on Kamala,” Fernandez said. “What I learned this week is, literally, we all have a part, and we have to keep doing that. We have to make sure we stay engaged. We’re in this together.”

Childs, 42, admitted she’s probably not going to volunteer. But she said Harris’ nomination acceptance speech had a real effect on her.

“It got me motivated to tell other people about her,” said Childs. “Hear what her policies are and encourage them to, you know, tap in.”

Neither doubted that Harris will be able to run a high-energy, inspiring campaign all the way to November. Referring to Harris having just become the nominee after President Joe Biden dropped his reelection bid last month, they compared her to an Olympic athlete wrapping up a relay race, coming in to grab the baton and run the final lap for the team.

“She ain’t on no hangover,” said Fernandez, perking up as she talked. “She should still be on her high. She can get us to this finish line. Everybody else has been running a marathon. She fresh. She stretching. She good.”

Although the race remains tight, Democrats do have reasons to feel pretty damn good right now. Pollsters in both parties have been watching in awe as Harris’ last-minute entrance in the race has dramatically upped the chances of Democrats winning the White House.

“We went from 1-in-3 to 50-50,” Jill Normington, a seasoned Democratic pollster and partner at Normington Petts & Associates, told HuffPost. “That’s a massive shift in a short amount of time.”

During a Wednesday panel of pollsters at the convention, Normington noted that recent polling shows women and young voters in particular being excited about Harris.

“We just see a sea change in enthusiasm, in intention to vote,” she said. “You take those two things together, and you’re looking at a radically different race now than a month ago.”

Abortion rights, too, is a driving factor in this election cycle, and in a way that benefits Harris. Polls show that Americans are overwhelmingly furious about Roe v. Wade being overturned by a conservative-majority Supreme Court in 2022 and about the subsequent chipping away of women’s reproductive rights in various states.

“There is a maxim in American politics, which is that angry people vote,” Normington said during her panel. “The Republican Party has never had to experience a presidential election where the anger on that issue was on our side.”

But though Democrats’ new hope and joy are real, it does not mean Harris has this in the bag.

“Everyone within the campaign and every practitioner still wakes up in a cold sweat,” said Evan Roth Smith, a Democratic pollster at Blueprint, a public opinion research group. “We know this is a 4- to 6-point race.”

Still, it’s “extremely important” that Democrats are feeling genuine excitement over the prospect of Harris becoming president, he said, even if the trajectory of the race changes again, which it certainly could.

“You know what? We’re finally up. People are excited,” Smith said. “And you know what? Let’s give ourselves a week to pat ourselves on the back or reassure ourselves that this is worth going to the mat for.”

Some convention attendees dismissed the idea that Democrats, who were on an emotional roller coaster of joy and tears throughout the convention, aren’t fully grasping the work ahead to ensure that Harris wins.

“It’s supposed to be hard. It’s a very divided country,” said Hassan Martini, executive director of No Dem Left Behind, a group that advocates for rural Democrats.

“I will say that we are fortunate enough to say that it’s going to be close. A couple of months ago, we were not as optimistic,” Martini said. “This, I believe, is the most difficult election of our lifetime. The last one is the most consequential. This one’s going to be the hardest.”