Does Kamala Harris have what it takes to beat Donald Trump?

The way is clear for Vice President Kamala Harris to secure the Democratic presidential nomination.

That may be the easy part. The toughest challenge—defeating Republican nominee Donald Trump in November—lies ahead. His rise to the top spot would give Democrats new strengths, but it would also expose weaknesses that Mr. Biden was less concerned about.

According to the latest polls, Ms. Harris is slightly behind the former president — a position roughly similar to where Mr. Biden was before his historic announcement. But those numbers could change as we move from a hypothetical showdown to a real one.

For at least a moment, Democrats found renewed energy after more than three weeks of intense concern about the president’s fitness and his ability to sustain his campaign.

All of Ms Harris’s main potential rivals for the nomination have endorsed her, as has former House Speaker Nancy Pelosi, who remains one of the most influential players in Democratic politics.

The race for the November election is shaping up to be tight, a situation that reflects the deep partisan divisions in American politics and the distaste many voters have for Trump as a candidate.

The vice president’s main challenge — and opportunity — will be to capitalize on that aversion to Trump, attracting centrist voters in key states and energizing the Democratic base, which has been tilting toward despair in recent weeks, to match the enthusiasm that many on the right have for the former president.

This surge in Democratic enthusiasm for the presidency comes with a dollar sign. According to the Harris campaign, the vice president raised more than $80 million (£62 million) in new donations in the 24 hours after Mr Biden’s announcement – ​​the largest single-day total of any candidate this election cycle. That, plus the nearly $100 million she inherits from the Biden-Harris fundraising coffers, gives her a solid financial footing for the campaign ahead.

Ms. Harris, if nominated, also defuses one of the most effective attacks Republicans have launched against their opponent: her age.

For months, the Trump campaign has criticized Mr. Biden as weak and easily confused — characterizations that were reinforced for many Americans after the president’s faltering debate performance four weeks ago.

The vice president, at 59, will be a more energetic campaigner and able to defend her party more coherently. She could also turn Trump’s age, 78, against him, as he would become the oldest person ever elected president.

Ms Harris may also be able to shore up support among black voters, who polls have shown have drifted away from Mr Biden in recent months. If she can combine that with increased support from other minorities and younger voters — Barack Obama’s winning coalition in 2008 and 2012 — it could help her gain ground against Trump in the handful of key swing states that will decide this year’s election.

Her experience as a prosecutor could also bolster her standing as a strong advocate for tough crime. While her background in law enforcement was a liability when she ran for the Democratic presidential nomination in 2019 — and drew mocking attacks from the left, such as “Kamala is a cop” — it could help her in her campaign against Trump.

The vice president has also been the administration’s leading voice on abortion, which has proven to be one of the most motivating issues for the Democratic base in recent elections. Mr. Biden, by contrast, has at times been reluctant to champion the issue, hampered by his history of supporting some restrictions on the procedure.

“I think she reminds suburban women all across the country, particularly in key states, what’s at stake when it comes to reproductive rights,” former New York Congressman Steve Israel, who led the Democratic Congressional Campaign Committee, told the BBC’s Americast podcast.

“We have implemented a fundamental reset of the campaign.”

For all of Harris’s potential assets, there’s a reason some Democrats were initially reluctant to push Mr. Biden to step aside, given that his running mate would be the obvious successor.

Despite the Democratic Party’s enthusiasm on abortion, Harris’s record as vice president has been mixed. Early in her term, she was tasked with addressing the root causes of the migrant crisis at the U.S.-Mexico border. A number of missteps and misstatements — including an awkward June 2021 interview with NBC News anchor Lester Holt — have damaged her reputation and exposed her to attacks from conservatives.

Republicans are already condemning her as the president’s “border czar,” trying to make her the face of what opinion polls have shown to be the Biden administration’s unpopular immigration policies.

“Immigration is a weak point for Democrats in these key areas,” Israel said. “It’s a very important issue for voters who live in these suburbs, rightly or wrongly. They feel that our immigration system is not being managed rigorously enough.”

The Trump campaign will also try to turn the vice president’s experience as a prosecutor against her, both by highlighting the former president’s record on criminal justice reform and by attacking her past decisions on prosecutions and parole.

Another vulnerability for Harris is her mixed record as a candidate. In her 2016 Senate bid, she faced only token opposition from Republicans in deeply Democratic California.

Her only attempt at a national election campaign—running for the Democratic presidential nomination in 2020—ended in failure. While she quickly gained momentum, a combination of botched interviews, a lack of clear vision, and a poorly managed campaign led her to drop out before the first primary.

Perhaps the biggest challenge for Ms. Harris is that, unlike the president, she is not the incumbent. While she has the opportunity to distance herself from some of the more unpopular elements of Mr. Biden’s record, she also does not have the luxury of being known to voters.

Expect a fierce attempt by Republicans to portray Ms Harris as too inexperienced and too risky to be president. In fact, Trump now has greater claims to be the only proven candidate.

The vice president has a chance in the coming days to make another first impression on the American public. If she fails early on, it could open the door to a protracted power struggle that would stretch into the Democratic National Convention in late August. The party could then unite behind another candidate, or tear itself apart.

As the past four weeks have shown, the race for the White House can swing quickly and permanently. Harris has punched her ticket to the biggest stage in American politics. Now she must prove she can compete.