Vice President Harris has had an extraordinary week — a campaign-changing stretch that has unified and energized Democrats, flummoxed former president Donald Trump and upended the 2024 election. She has 100 days to convert all that into a winning campaign.

Robby Mook, who was campaign manager for Hillary Clinton in 2016, said Harris had a “perfect 48 hours” after President Biden announced last Sunday that he was ending his candidacy. Her rapid consolidation of support was almost breathtaking in its velocity and effectiveness.

Buckets of money flowed into the campaign. Tens of thousands of people volunteered to help. Leading Democrats and allied organizations moved to endorse her in a well-choreographed sequence that culminated with former president Barack Obama and his wife, Michelle, on Friday. Harris pivoted from a secondary role to leading the attack against Trump, bringing force and focus that Biden struggled to show.

Talk of assuring an open process to select a new nominee and open doubts about her electability melted away overnight. Potential rivals for the nomination endorsed Harris rather than challenge her. Those who might have considered doing so likely were chastened by the rush to embrace the vice president’s historic candidacy.

A party divided and demoralized ever since Biden’s faltering June 27 debate performance regained hope that Trump now might be beatable. Initial polls, which will be far from the last word on the subject, show Harris running better than Biden, though not with any clear lead.

Harris’s ascent has had a notable impact especially on many women voters. Over the past week, I reached out to women in the Denver and Atlanta suburbs whom I have interviewed in the past to get a better sense of the reaction. Some of those around Denver I first met during the 2018 midterm elections and then sought their views during the 2022 campaign. Those in Georgia were part of a group of Black voters I met in the months before the 2022 midterm elections.

Robin Kupernik, who lives in the Denver suburbs, became a political activist after Trump was first elected in 2016 and has remained so ever since. Her reaction to the shift from Biden to Harris spoke for many women.

“People in my orbit are over the moon,” she said in a text message. “We are so excited to have a fighting chance again. My sister says she thinks this will be our finest hour. My daughter says young people who were apathetic before are now engaged.” Listening to Harris, she said, “makes me tear up.”

In 2022, during a conversation at a public library in Littleton, Colo., Katie Skinner expressed the hope that Biden would not seek a second term. “I always felt like he would just be a one-term president, especially because of his age,” she said at the time. “I would like to see another Democrat in office and maybe somebody just of the newer generation,” she said then.

Biden’s decision is like a burden lifted. “I feel reinvigorated, excited and laser focused on supporting her and seeing this through,” she said in an email last week. “With Biden at the top of the ticket, I felt like I was holding my breath for months. Sunday felt like a big exhale, and now I’m breathing steady.”

Jen Helms, who lives in Denver, was so worried about Biden’s frailties that she tried never to watch him speak. For that reason, she did not watch the Atlanta debate with Trump. “I only saw clips of the debate, and that was enough,” she said in an email. “He just seemed already defeated.”

She is learning more about Harris, likes what she has seen and appreciates the burst of energy inside the Democratic Party. But she has reservations about what comes next. “I’m relieved Joe stepped down ultimately, but anxious about our ability to get Kamala elected.”

In the fall of 2022, many of the suburban women interviewed around Denver were focused on the Supreme Court’s decision in Dobbs v. Jackson Women’s Health Organization, which ended half a century of the constitutional right to abortion. Lindsey Zaback was one, saying at the time, “I think that this coming election [2022], women are going to be out in full force.”

In a telephone interview a few days ago, as she talked about her reaction to Harris as the likely nominee, Zaback pointed specifically to the issue of abortion in this year’s election. “What’s happened in our country is a complete tragedy,” she said, referring to the decision overturning Roe v. Wade. “We need a leader that will make fixing this a priority. [Harris] has a proven track record … and I think it’s really important that we have someone that will prioritize that for women.”

If the abortion issue has energized Democrats since 2022, the Israel-Gaza war over the past nine months has fractured the party’s coalition, with many younger Democrats believing that Biden has not been forceful enough in condemning Israel’s conduct and the civilian casualties that have resulted.

Cori Detwiler, another suburban Denver resident, sees Harris as a better nominee than Biden but wondered whether the vice president can patch up the divisions. “I am hopeful that him stepping down will reengage a portion of the Democratic [and] Democratic-leaning voters that have been disenchanted with Biden’s policies (especially with the handling of Israel’s occupation of Gaza),” she said in a text. “I worry Kamala isn’t far enough removed from those policies to fully reinvigorate those voters though.”

Black women have been the most reliable voters in the Democratic coalition, and they have responded to Harris’s emergence. Darlena Slate of Peachtree Corners, Ga., in suburban Atlanta, was keeping her distance from the campaign, fearful that the election was moving in Trump’s direction. When she heard that Biden had dropped out and endorsed Harris, she said, “I was in disbelief because I was thinking, wow, he actually nominated a Black woman to be his replacement and ask the country to stand behind her.”

With Harris as the likely nominee, Slate is more committed to help. “Now that we as Black women have a strong Black woman candidate running for president of the United States, I personally will be even more engaged.”

Dennisha Haynes of Lawrenceville, Ga., has run the gamut of emotions this election year, from anger that the party was left with Biden as the sole candidate to panic that the conversation about replacing him was coming so late to trepidation mixed with cynicism that if Harris were not the nominee it would be “a slap in the face” to the vice president and by implication to Black women like her.

“I am now at excitement but am still cynical,” she said in a text message. “I believe wholeheartedly she has what it takes to win and do a great job. She’s exactly what we need. But she is a Black woman in America and this country hasn’t always viewed us as it should.”

Kelly Martin, who is Black and lives in Gwinnett County outside Atlanta, said she was so unenthusiastic about a Biden-Trump race that she was thinking about abstaining from voting for president this fall. Harris’s emergence has made her look at the campaign differently. She said she can “feel the energy shifting,” adding: “Right now I am hopeful, but I have learned that sometimes hope bites me in the end.”

Her larger worry is what would happen if Harris were elected. “I really think that it’s going to divide us even more,” she said. “I think that we are on the precipice of a civil war. … What she represents as a woman and person of color and having the highest position in the land will inflame a lot of people.”

Two years ago, Jasmine Clark, a Georgia state representative, said that Biden had done “a great job” but that in 2024, she believed “it would be better if we lifted up someone else, someone younger.” Now, as a Georgia delegate to the convention, she is excited to cast her vote for Harris. But she also worries about what Harris will face in the months ahead.

“As a Black woman, I am bracing for the inevitable racist and sexist attacks on her and have mixed emotions about us asking her to sprint a marathon and do something unprecedented in an impossibly short timeline,” Clark said. “But I am also extremely hopeful that she can pull this off.”

Clark and the other Black women recognize how difficult the coming months could be for Harris. She has had an impressive opening week, but when she ran for president in 2020, she had a similarly strong start to the campaign, only to falter as the months went on. In that campaign, she struggled to offer a vision or explain her core convictions.

She will have to weather attacks about positions she has taken in the past and move to define herself before Trump’s campaign does it for her. In the past few days, she has shown that she can prosecute a case against Trump. But is she as good a defense attorney as she is a prosecutor?

Harris has big decisions ahead, starting with the selection of a running mate and then whether and how to differentiate herself from Biden and his policies. She offered some hint of that on Thursday after a meeting with Israeli Prime Minister Benjamin Netanyahu, delivering pointed words about Israel’s conduct of the war against Hamas in Gaza.

The campaign has changed overnight from one that has been largely backward looking and featuring the two oldest and least popular candidates in history to one that will pit the future against the past. But is Harris a change candidate or merely a continuation of what Biden has been and done?

Her skills as a candidate will be tested, which is why one week is too soon to predict what this contest might look like in October.