CHICAGO (AP) — Vice President Kamala Harris closes out the Democratic National Convention Thursday night when she accepts her party's historic presidential nomination and seizes one of her few remaining opportunities to appeal to an audience of millions.

Harris will lay out her vision for the country and prosecute her case against Republican Donald Trump, capping a whirlwind month that began when President Joe Biden ended his reelection bid and endorsed her to replace him atop the Democratic ticket.

Harris has three objectives for her speech, according to a campaign official who spoke on condition of anonymity to discuss sensitive speech preparations. She'll share her background rising from a middle-class family to protect others as a prosecutor, contrast her "optimistic" vision with Trump's "dark" agenda and evoke a sense of patriotism, the official said.

Harris spoke briefly to the convention on Monday, when she thanked Biden and celebrated his record as president, and again on Tuesday, when the beginning of her rally in Milwaukee was streamed into the convention hall after Democrats reaffirmed their nomination of her with a state-by-state roll call.

Among others who will speak before Harris on Thursday are Michigan Gov. Gretchen Whitmer, North Carolina Gov. Roy Cooper, civil rights leader Al Sharpton and Randi Weingarten, president of the American Federation of Teachers.

Former Reps. Adam Kinzinger, an Illinois Republican who has bucked his party to oppose Trump, and Gabby Giffords, the Arizona Democrat who was nearly killed in a mass shooting in 2011, are also scheduled to speak. The singer Pink is slated to perform.

Harris, the daughter of immigrants from Jamaica and India, will be the first Black woman and the first person of South Asian descent to accept a major party's presidential nomination. If elected, she would be the first female U.S. president. She'll speak a day after Minnesota Gov. Tim Walz, her choice for running mate, thanked the packed Chicago arena for " bringing the joy " to the election.

"We're all here tonight for one beautiful, simple, reason: We love this country," Walz said as thousands of delegates hoisted vertical placards reading "Coach Walz" in red, white and blue.

Many Americans had never heard of Walz until Harris made him her running mate, and the speech was an opportunity to introduce himself. He leaned into his experiences as a football coach, his time in the National Guard and his recounting of his family's fertility struggles — including parts of his biography that Republicans have questioned in the days since Harris picked him.

While it's unclear if the speech will attract new voters, he further charmed Democratic supporters with his background and helped to balance Harris' coastal roots as a cultural representative of Midwestern states whose voters she needs this fall.

Gus Walz, the governor's 17-year-old son, openly wept throughout the speech, wiping his eyes with tissues while watching from the front row of the convention hall directly in front of the governor.

Through tears he mouthed, "That's my dad."

Despite Harris' prominence as vice president, she's spent four years in Biden's shadow, leaving some Americans unclear on her personal history and her political vision for the country.

Republicans have raced to fill in the gaps, accusing Harris of being a "communist" and "dangerously liberal." Trump has also targeted her race, while his running mate JD Vance describes her as a "chameleon."

Harris' team has emphasized her law enforcement background, including her time as San Francisco district attorney and California attorney general. She was later elected to the U.S. Senate and sought the Democratic presidential nomination in 2020.

Her campaign imploded that year before a single primary vote was cast, but Biden chose her as his running mate, catapulting her to the national stage.

Although Harris initially struggled as vice president, her reputation grew when she became the administration's leading advocate for abortion rights after the U.S. Supreme Court overturned Roe v. Wade. Democrats harnessed anger over the decision to stem their losses in the last midterm elections.

When Biden stumbled in his debate with Trump in June, Harris defended him until he decided to drop out of the race. With the help of his endorsement, she swiftly unified the Democratic Party behind her candidacy, resetting a presidential race that Trump had appeared on track to win.

"We know what we're dealing with in this moment," Harris said this week in Milwaukee. "And we must remember — as the generations of Americans before us who led the fight for freedom — the baton is now in our hands."

___

Cooper reported from Phoenix. Associated Press writer Chris Megerian contributed from Washington.