It was the first time that Vice President Kamala Harris and President Joe Biden appeared at an event together since the president finished his second term and Harris took over for Biden as the Democratic nominee.
The event, held just outside Washington, DC, coincided with Donald Trump speaking at a press conference in New Jersey, his second campaign event in the past two days.
The Democratic event on Thursday celebrated the Biden administration’s newly announced agreement to lower the prices of 10 common prescription drugs taken by millions of Americans.
It also offered a glimpse into the dynamics between the two men, weeks into the party’s realignment.
The White House said about 2,300 people attended a rally Thursday in Upper Marlboro, Maryland, a Democratic stronghold.
“I have a great partner in the progress we’ve made,” the president said. “She’ll be a great president.”
But beyond the policy announcements, Biden offered encouragement to his vice president, who repeatedly brought the audience to their feet.
The warm feelings were mutual.
“There’s a lot of love in this room for the president,” Harris said. “Few leaders in this country have accomplished as much as Joe Biden has on so many issues, including expanding access to affordable health care.”

Thousands of people lined up in the summer heat to hear Biden and Harris speak, with videos on social media showing hundreds still waiting after the venue was filled to capacity.
The event was the latest in a series hosted by Harris that drew large crowds of supporters and signaled a notable shift in energy around the presidential campaign.
But Harris has largely avoided media questions and has not given a single interview since becoming the party’s nominee.
The enthusiasm of her supporters is also reflected in the polling data: A recent survey by the Cook Political Report found that Harris is narrowing polling leads over former President Donald Trump in Arizona, Michigan, Pennsylvania and Wisconsin.
Vivian Strong waited three hours to get into Thursday’s event and told the BBC she hoped to be present for the historic moment.
“I feel a sense of urgency to make sure she gets elected,” she said. “I don’t want to see another person take power.”
Before the president and vice president took the stage, supporters from Howard University, the historically black college in Washington, D.C., where Harris attended, led the crowd in chants.
Many of the vice president’s supporters wore pink and green, the colors of Harris’s Alpha Kappa Alpha Sorority (AKA).
Linda Jones, a Howard University graduate and AKA member, said she was excited about the shared identity, but also said she was eager to hear Biden speak.
“I’m pleased that President Biden has delivered on something he’s worked so hard for,” Jones told the BBC about the prescription drug deal.
“I was really sad to see him leave behind a dark shadow because he’s such a good guy. So now I think (this policy) is another encouragement for him.”

Meanwhile, President Trump, speaking from his golf resort in Bedminster, blasted Ms Harris in his second news conference in recent weeks.
He claimed he had the “right to attack” Harris personally, touching on key themes of his own campaign and attacking her record on inflation, crime and immigration.
“How can a family afford that?” Trump asked, standing in front of a typical grocery store display with signs showing prices have gone up in recent years.
U.S. inflation rose at the slowest pace in more than three years last month, providing relief to consumers and the top financial concern for many Americans.
“You don’t have to imagine what it would be like if Kamala Harris were president, because you’re living that nightmare right now,” Trump said.
“I don’t have much respect for her. I don’t have much respect for her intelligence,” he said, adding: “People say, ‘Be nice,’ but they’re not nice to me. They want to put me in jail.”
Earlier on Thursday, US media reported that the Secret Service would use bulletproof glass to protect Trump whenever he gives outdoor campaign speeches.
The measure is normally applied to sitting presidents, but an exception was made following the attempted assassination of Trump in Pennsylvania last month.
The Secret Service declined to comment on the report.

