CHICAGO, United States (AFP) — Kamala Harris and Donald Trump set out Friday on the final 10-week sprint to election day, with the Democrat surging after an electrifying speech accepting the Democratic Party nomination.

Less than three weeks before the presidential debate between the United States (US) vice president and the Republican ex-president — and only a month before early in-person voting begins — polls show the race for the White House is neck and neck.

The former senator and prosecutor leaves Chicago with the wind in her sails, having outraised Trump and erased the polling leads he was enjoying before she replaced President Joe Biden atop the Democratic ticket last month.

But Dan Kanninen, battleground director of the Harris campaign, cautioned at a Bloomberg event on the sidelines of the convention that the race “is not fundamentally changed” and still “very, very tight”.

“We have tremendous enthusiasm — I think momentum is on our side — but we now need to do something with it and engage the electorate effectively this fall,” he said.

Harris accepted her party’s presidential nomination on a glitzy final night in Chicago, buoyed by a galaxy of stars, that set the stage for the gruelling run-in to November 5.

The 59-year-old Californian has edged ahead by razor-thin margins in polling, reversing what had started to look like a likely Trump victory against Biden before he dramatically pulled out and endorsed Harris.

In just a month, Harris has raised a record-breaking half a billion dollars, enjoying a political honeymoon that shows little sign of ending.

Party leaders have cautioned that headwinds could still buffet the campaign, however.

These include internal protests over US policy on the Israel-Hamas war and possible shifts in polling with the expected withdrawal on Friday of independent candidate Robert F Kennedy Jr, who may endorse Trump.

The controversial scion of America’s revered Kennedy clan is planning an announcement in Arizona, while Trump is also campaigning in the state, and promising to showcase a “special guest”.

Analysts are mixed on the effect a Kennedy exit would have.

He is polling in the low single digits and his embrace of conspiracy theories has made him a fringe figure.

However, in a very tight race, it is possible that even a few thousand votes in a crucial swing state could ultimately determine who takes the White House.

Democratic heavy hitters, from Michelle Obama and Bill Clinton to vice presidential nominee Tim Walz, have warned that the party could still lose to Trump’s Republicans if complacency creeps in.

“If we see a bad poll — and we will — we’ve got to put down that phone and do something,” the former first lady told the party faithful in Chicago.

Walz, a former school football coach, used a sporting analogy, saying that Democrats were “down a field goal, but we’re on offense and we’ve got the ball.”