WILMINGTON, Del. (AP) — Joe Biden and Kamala Harris delivered an aggressive one-two attack on the character and performance of President Donald Trump on Wednesday, as they made their election case for the first time as running mates.

Biden, a 77-year-old white man, embraced the significance of naming the first Black woman to a major party’s presidential ticket, but he also focused on other attributes Harris brings to the ticket. He hailed the California senator, the 55-year-old former prosecutor who a year ago excoriated Biden on a primary debate stage, as the right woman to help him defeat Trump and then lead a nation facing crises in triplicate: a pandemic, wounded economy and long-simmering reckoning with racism.

Harris, Biden declared at a high school gymnasium in his hometown of Wilmington, Delaware, is “smart, she’s tough, she’s experienced, she’s a proven fighter for the backbone of this country.”

“Kamala knows how to govern. She knows how to make the hard calls. She’s ready to do this job on day one,” he said.

Reflecting the coronavirus pandemic, both candidates came onstage wearing protective masks in a high school gym with relatively few in attendance, not in a hall filled with cheering supporters as would normally be the case. Both spoke without masks but did not physically embrace.

Biden praised her experience vigorously questioning Trump administration officials in the Senate, and highlighted the historic nature of her pick, noting she’s the daughter of immigrants from India and Jamaica.

“This morning, all across the nation, little girls woke up — especially little black and brown girls, who so often feel overlooked and undervalued in their communities. But today, today, just maybe, they’re seeing themselves for the first time in a new way,” Biden said.

Harris sat feet away from Biden, listening with her protective mask off.

Taking the stage after him, she flicked at some of the gender critiques she’d faced throughout the Democratic primary, saying she was “mindful of all the ambitious women before me, whose sacrifice, determination and resilience makes my presence here today even possible.” She then launched into an attack on Trump, lambasting him for a lack of leadership on the coronavirus pandemic.

“This is a moment of real consequence for America. Everything we care about — our economy, our health, our children, the kind of country we live in — it’s all on the line,” she said.

Biden and Harris showed clear affection toward one another, with Biden calling her an “honorary Biden” and Harris offering an emotional tribute to his son Beau, whom she was friends with when both served as attorneys general. Biden seemed overcome with emotion as Harris spoke of Beau, who died in 2015, as “the best of us” and a man who modeled himself after his father.