Vice President Kamala Harris has done almost everything right since President Joe Biden announced a month ago that he was ending his candidacy. But as Democrats prepare to open their national convention in Chicago on Monday, the question is this: Has she done enough to win the election?

Harris has flipped the script on the presidential election, able to run as a new generation candidate. She and her running mate, Minnesota Gov. Tim Walz, are drawing huge and enthusiastic crowds and raising massive sums of money. Former president Donald Trump has been confounded by the switch from Biden to Harris and is flailing, unhinged in many of his comments and, for now at least, unable to deliver a disciplined, coherent message.

The polls have shifted in Harris’s favor, but for all that, the presidential contest is a toss-up. Some Democrats warn that too many in the party may be suffering from irrational exuberance about her chances of winning. “She’s had the best four weeks in modern American political history, and we’re still basically in a tied race,” said one Democratic strategist, who spoke on the condition of anonymity to offer a candid assessment.

Harris has drawn universally positive assessments from Democrats, and good marks from some Republicans, for how she has handled her sudden elevation as the party’s presidential nominee. But questions remain about her. What and how does she think about most issues? Where would she take the country? Would she separate herself from Biden, and how? How would she reconcile her past and current positions? How well prepared is she for the inevitable potholes ahead?

Those questions will be answered only in part at the Chicago convention. The four-day event will be almost entirely celebratory, lights-years different in mood from what it would have been with Biden as the nominee. The program will amount to a nightly infomercial designed to say a polite, respectful goodbye to the current president and introduce Harris to millions of voters who may know little about her other than that she is vice president.

Her speech Thursday night will cap the convention. When the Republicans gathered in Milwaukee for their convention last month, Trump squandered an opportunity on the final night to build on the previous three nights of unity with a rambling, too-long acceptance speech. Harris can’t afford to waste her moment, though there’s little likelihood that she will go off script the way Trump did. She has rarely departed from the words on the teleprompter in the past four weeks.

The speech will let her tell her own story. As the first woman of color to head a national ticket, she presents a unique biography. What she says about how she grew from the daughter of a mother from India and a Black father from Jamaica to the presidential nominee 59 years later offers a potentially rich narrative about a changing and diverse America, one in which opportunity abounds. The fact that people know little about her, as one strategist put it, is both “a wonderful opportunity, but it’s also kind of a warning.”

In retrospect, Harris has been lucky in the timing of all this. Had Biden quit the campaign earlier in the year, Harris might have faced competition for the nomination, or a longer and more difficult introductory period. With Biden leaving the race when he did, Harris was able to dominate the presidential election discussion for the last week of July through her convention — and probably will right up to Labor Day.

Doug Sosnik, a former Clinton administration official and a Democratic strategist, noted in a memo released Friday that “Harris has not lost a single news cycle since she announced that she was running for president on July 21st. At times it appears that she is leading more of a movement than a political campaign.”

Her convention speech will be one indication of how she navigates the issue of being tied to Biden and his administration’s record while also defining herself as separate and apart from him. She is not the first vice president to confront this. The risk is that Trump and the Republicans turn her into a continuation of the Biden presidency and force her to own some of the administration’s least-popular policies.

Harris has only begun to fill out her ideological profile. On Friday, she unveiled an economic program focused on lowering prices, a set of populist ideas that build on the policies of the Biden administration and that includes a proposed ban on price gouging by grocers. The plan also includes a proposal to eliminate medical debt, a cap on prescription drug prices, a child tax credit and incentives for first-time home buyers.

The proposed gouging ban is likely to be popular with Americans burdened with higher prices, but it represents a further intervention into the economy by the government without a clear prospect for success. Its effectiveness would depend on so-far unspecified details.

Harris staked out liberal positions on a number of issues as she ran unsuccessfully for the Democratic nomination in 2020. This time, Harris has not made any obvious moves to the center. On foreign policy, Harris has been somewhat more forceful than Biden in calling for a cease-fire in the war between Israel and Hamas, to the approval of her party’s left wing. The choice of Walz, who has a very progressive record as governor, rather than Pennsylvania Gov. Josh Shapiro, whose profile is more moderate, also reinforced her comfort with the party’s left flank.

Harris also has yet to explain her shifts onpositions she took in the run-up to the 2020 primaries and caucuses, among them opposing fracking; supporting a single-payer, government-run health-care system; and ending private health insurance. Her campaign has said she no longer holds those positions, but she has not talked about how and why she changed.

“She will have to reconcile some of the positions she took four years ago and the positions the Biden administration has taken that aren’t the same,” said Beth Myers, a Republican strategist and longtime top adviser to Sen. Mitt Romney (R-Utah). “That doesn’t mean she can’t do that, but it will be a challenge.”

Trump and his running mate, Sen. JD Vance of Ohio, have tried to paint the Democratic ticket as radically liberal, though Trump’s attacks threaten to get lost behind his barrage of lies, grievances and misinformation. But the risk for Harris is that, the more she is becoming known, the more people see her as very liberal, potentially compromising her ability to appeal to moderate voters.

Four weeks into her campaign, Harris has yet to do an interview or an extended session with reporters. Republican pollster Whit Ayres, acknowledging that “it’s hard to imagine a better start” to her campaign, said he wants to see how she handles unscripted moments. “There are numerous examples of her sounding utterly incoherent when she can’t have a teleprompter,” he said.

Harris has been a happy warrior as the party’s nominee, and Democratic strategists say she must do everything she can to maintain that posture. They argue that she should focus more on values and optimism — and on her time working at McDonald’s while in college — rather than multi-point plans about policies.

“Her task is pretty simple,” David Axelrod, who was chief strategist in both of Barack Obama’s presidential campaigns, said of her to-do list at the convention. “I don’t think there’s a majority of people who want to reelect Donald Trump president. She needs to make herself an acceptable alternative, and she has to introduce herself.”

Were Biden still the candidate, the convention would be overwhelmingly negative in tone — relentless in attacks on Trump as a threat to the country’s future and with many delegates downbeat over fears of losing. There will still be plenty of anti-Trump rhetoric from the stage all week. But Harris can take a different approach, seeking to move past Biden and presenting herself as the candidate who looks to the future. “She is the turn-the-page candidate, the one who will put the Trump era behind us and reduce the level of rancor and reknit the American community to some degree,” Axelrod added.

Trump has performed poorly since Biden quit the race, and perhaps may never find his footing against an opponent he didn’t expect to face. But strategists in both parties note that, in 2016, he floundered in August but became steadily more solid as a campaigner, surging past Hillary Clinton at the very end in the states that counted when it really mattered. Some Democrats worry that that could happen again.

“Everything [for Harris] has been charmed so far,” said a Democrat with experience in past campaigns. “It’s almost the exact opposite of Hillary — everything was litigated and questioned.” Harris, in contrast, has been given “a total benefit of the doubt” and an extended honeymoon period, he said, adding, “We know it can’t continue like that.”

Democrats expect the good times to roll throughout the coming week and into the week beyond. Then, they say, reality will set in.