Harris posted a photo of her watching the second gentleman's speech at the DNC Tuesday night.

"Love you, Dougie," she wrote on the social media post.

After more than 30 minutes on stage, Obama had a simple message for convention-goers.

"As much as any policy or program, I believe that’s what we yearn for, a return to an America where we work together and look out for each other," Obama said.

"That is what this election is about," he added. "And I believe that’s why, if we each do our part over the next 77 days, if we knock on doors, if we make phone calls, if we talk to our friends, if we listen to our neighbors, if we work like we’ve never worked before, if we hold firm to our convictions, we will elect Kamala Harris as the next president of the United States and Tim Walz as the next vice president of the United States."

"So let’s get to work. God bless you, and God Bless the United States of America."

Turning personal, Obama spoke about the bond he had with Michelle Obama's mother, who passed away earlier this year.

"One of the reasons Marian and I became so close was she reminded me of my grandmother, the woman who helped raise me as a child," he said.

"They were strong, smart, resourceful women, full of common sense who, regardless of the barriers they encountered ... In that sense, they both represented an entire generation of working people who, through war and depression, discrimination and limited opportunity, helped build this country," he said.

Obama said to build a true Democratic majority, they have to give grace to people who may not align with their political views.

"That sense of mutual respect has to be part of our message," he said. "Our politics have become so polarized these days that all of us across the political spectrum seem so quick to assume the worst in others unless they agree with us on every single issue."

"We start thinking that the only way to win is to scold and shame and out-yell the other side. And after a while, regular folks just tune out or they don’t bother to vote," he continued. "Now that approach may work for the politicians who just want attention and thrive on division, but it won’t work for us to make progress on the things we care about, the things that really affect people’s lives."

Obama later acknowledged those ideas "can feel pretty naive right now" but was adamant "the ties that bind us are still there."

Vermont Sen. Bernie Sanders, an independent, highlighted some of the Biden-Harris accomplishments they made since coming to the White House in the midst of the COVID-19 pandemic, from expanding Medicaid to providing rent relief and mortgage relief to protecting union workers' pensions.

"When the political will is there, government can effectively deliver for the people of our country," he said. "We need to summon that will again -- because too many of our fellow Americans are struggling every day to just get by -- to put food on the table, pay the rent, and get the health care they need."

"Bottom line: We need an economy that works for all of us, not just the greed of the billionaire class," he said to applause.

He said, though, that more needs to be done and laid out a progressive agenda. At the top of that to-do list, he said, is to "get big money out of our political process." He called for the "disastrous Citizens United Supreme Court decision" to be overturned, as well as increasing the minimum wage and more prescription drug cost cuts.

"I look forward to working with Kamala and Tim to pass this agenda," he said. "And let us be clear. This is not a radical agenda. But, let me tell you what a radical agenda is. And that is Trump’s Project 2025. Giving more tax breaks to billionaires. Putting forth budgets to cut Social Security, Medicare and Medicaid. Letting polluters destroy our planet. That is what is radical. And we won’t let it happen."

He also called for an immediate cease-fire in Gaza and the return of hostages, to applause from the crowd.

Sanders, who was slower to endorse Harris for the presidency, ran for president himself in 2016 and 2020.