With the White House illuminated behind her, Kamala Harris asked the vanishing slice of undecided Americans to elect a “new generation of leadership”, likening Donald Trump to a “petty tyrant” who had stood in the very same spot nearly four years ago and, in a last-gasp effort to cling to power, helped incite the mob that stormed the US Capitol.

The choice between her and Trump in the deadlocked presidential contest was “about whether we have a country rooted in freedom for every American or ruled by chaos and division”, Harris said, from the Ellipse near the White House’s South Lawn, where tens of thousands of supporters gathered one week before the final votes of the 2024 election are cast.

“I ask for your vote,” she told the crowd, which spilled beyond the park, toward the Washington monument, and the many more watching at home.

In a speech her, campaign billed as the former prosecutor’s “closing argument” with the American people as her jury, Harris repeatedly gestured behind her as she described the progress she hoped to make as the 47th president of the United States on lowering prices, protecting abortion rights and addressing immigration.

“In less than 90 days, either Donald Trump or I will be in the Oval Office,” she said as the crowd – which the campaign placed at 75,000 – erupted into chants of “Kamala! Kamala!” “On day one, if elected, Donald Trump would walk into that office with an enemies list,” she continued. “When elected, I will walk in with a to-do list.”

The oval-shaped park also served as reminder of Trump’s actions on January 6, when he exhorted his followers to “fight like hell” and walk to the Capitol where Congress was certifying Joe Biden’s 2020 victory. Aggrieved and “obsessed with revenge”, Trump was “out for unchecked power” , Harris warned, charging that he would spend the next four years focused on his problems, not the country’s.

Although Harris framed the stakes of the 2024 election as nothing less than the preservation of US democracy, she sought to offer an optimistic and hopeful tone, in stark contrast to the dark, racist themes that animated Trump’s grievance-fueled rally at Madison Square Garden. Harris called on Americans to “turn the page” on the Trump era and “start writing the next chapter in the most extraordinary story ever told”. Americans had forgotten, she said, that “it doesn’t have to be this way”.

From his Mar-a-Lago club in Florida earlier on Tuesday, Trump waved off criticism of the rally, calling it an “absolute love fest”.

The daughter of immigrants from India and Jamaica, Harris recalled attending civil rights marches with her parents as a toddler and the memory of her mother, “a cup of tea in hand”, poring over bills at the kitchen table.

“I’ve lived the promise of America,” Harris said, and without an explicit reference to the history-making nature of her candidacy, she grounded it in a fight for “freedom” that has propelled generations of “patriots” from Normandy to Selma, Seneca Falls and Stonewall.

“They did not struggle, sacrifice, and lay down their lives only to see us cede our fundamental freedoms, only to see us submit to the will of another petty tyrant,” she said, her voice building as she declared: “The United States of America is not a vessel for the schemes of wannabe dictators.”

In recent days, Harris has amplified warnings of her opponent’s lurch toward authoritarianism and open xenophobia. Her campaign is running ads highlighting John Kelly, a marine general and Trump’s former chief of staff, saying that Trump met the definition of a fascist. Harris has said she agrees.

In her remarks, Harris attempted to balance the existential and the economic – focusing on the threat Trump poses to US institutions while weaving in her plans to bring down prices and build up the middle class. She portrayed Trump as a tool of the billionaire class who would eliminate what is left of abortion access and stand in the way of bipartisan compromise when it does not suit him politically.

Responding to her Ellipse speech, a Trump campaign spokesperson accused the vice-president of “lying, name-calling, and clinging to the past”.

Polls show the contest between Trump and Harris virtually tied in the seven battleground states like to decide the presidential election.

Trump has sought to rewrite the history of January 6, the culmination of his attempt to cling to power that resulted in the first occupation of the US Capitol since British forces set it on fire during the war of 1812. Trump recently declared the attack a “day of love” and said he would pardon the January 6 rioters – whom he has called “patriots” and “hostages” – if he is elected president.

Hundreds of supporters have been convicted and imprisoned for their conduct at the Capitol, while federal prosecutors have accused Trump of coordinating an effort to overturn his 2020 election loss to Joe Biden. Trump maintains that he played no role in stoking the violence that unfolded, and still claims baselessly that the 2020 election was stolen from him.

In a press call on Tuesday morning, Harris’s campaigned expressed a bullishness about her prospects. “We know that there are still a lot of voters out there that are still trying to decide who to support or whether to vote at all,” Jennifer O’Malley Dillon, Harris’s campaign’s chair, told reporters before her remarks on Tuesday. She said many Americans were “exhausted” by the tribalism and polarization Trump has sharpened since his political rise in 2016.

In an abbreviated 100-day campaign that Harris inherited from Biden after he stepped aside in July, the Democratic nominee has unified her party, raised more than $1bn, blanketed the airwaves and blitzed the battleground states. And yet the race remains a dead heat nationally and in the seven swing states that will determine who wins the White House.

After her speech, Harris will return to the campaign trail, where she will keep a frenetic pace ahead of what her campaign has called a “margin-of-error election”.

“We see very good signs for us across the battleground states, in particular in the blue wall,” O’Malley Dillon said on the Tuesday morning call, referring to Wisconsin, Michigan and Pennsylvania, where Harris has barnstormed in recent weeks. “And we see that we’re on pace to win a very close election.”