WASHINGTON, July 29, 2024 (BSS/AFP) - The 100-day sprint to the US election began Sunday, the final act of a campaign transformed by an assassination attempt and the stunning exit of President Joe Biden.

After weeks of infighting and despondency over Biden's candidacy, Democrats have consolidated behind Vice President Kamala Harris, radically reshaping the race to November 5 that was fast becoming Republican nominee Donald Trump's to lose.

Harris's candidacy has clearly reinvigorated her party's campaign, which said Sunday it had raised $200 million -- mostly from first-time donors -- since Biden dropped out and endorsed his vice president a week ago.

A new Wall Street Journal poll showed Harris had closed Biden's six-point deficit with Trump to just two points -- well within the margin of error -- with boosted support from Black, Latino and young voters.

But Republican pollster David Lee, who conducted the Journal survey, cautioned Democrats not to get carried away by the race tightening.

"Donald Trump is in a far better position in this election when compared to a similar time in the 2020 election," Lee said.

If the race is at a dead heat nationally, the advantage still lies with Trump given the mathematics of the Electoral College system for electing the president.

Trump's 2016 victory over Hillary Clinton came despite losing the nationwide popular vote by nearly three million ballots.

- 'We are the underdogs' -

"We are the underdogs in this race," Harris acknowledged at a fundraising event on Saturday.

"But this is a people-powered campaign and we have momentum," she added.

Former vice president Al Gore on Sunday joined the parade of high-profile Democrats who have endorsed Harris, emphasizing her record on the environment.

The Democratic convention in mid-August will seek to keep that momentum going with a jubilant celebration of Harris's candidacy.

It all looked so different just a month ago.

Dogged by voters' concerns about his age and mental acuity, the 81-year-old Biden was an outside bet at best, trailing his predecessor in the first presidential election rematch since Dwight Eisenhower trounced Adlai Stevenson in 1956.

Biden's dismal June 27 debate performance ignited alarm and panic within his party.

The flames were fanned by a flawless show of unity behind 78-year-old Trump at the Republican National Convention -- an event galvanized by a gunman's failed bid, just days earlier, to assassinate the former president at a rally in Pennsylvania.

After an initial show of defiance, Biden bowed to the inevitable and dropped out of the race a week ago.

Harris, a generation younger at 59, threw her hat in the ring -- turning what had been a stale contest between two unpopular, aging, white male candidates into a dynamic and unpredictable showdown.

The final result on November 5 will likely be determined by around 100,000 independent, undecided voters in a handful of battleground states that both campaigns will target exhaustively over the coming three months.

- The Harris honeymoon -

The challenge for Harris is substantial. Once the Republicans have adapted to her candidacy and honed their attack lines, they are set to hammer her over key voter issues such as immigration and rising prices.

Democratic strategist James Carville told MSNBC that Democrats needed to cut the happy talk and prepare for the coming storm.

"They're coming at us and they're going to keep coming. And this kind of giddy elation is not going to be very helpful much longer because that's now what we're going to be faced with," he said.

Even former president Barack Obama has cautioned against hubris, underlining Harris's underdog status and the need for her to earn the trust of voters.

Trump, who has seen his favorability ratings tick upward since the July 13 attempt on his life and the successful Republican convention, made his attack priorities clear at a rally Saturday in the traditionally Democratic state of Minnesota.

Labeling Harris a "crazy liberal" and a "radical left lunatic," Trump lied to make her sound like an extremist on abortion and made fun of her laugh.

"We have a brand new victim," he told his cheering supporters.