Election 2020 updates: 'I think the mute is very unfair': Trump on debate mics

At the drive-in rally, Obama also issued a stern warning against Democratic complacency and said that the election has to be a decisive win as Trump sows doubts in its results.

"I don't care about the polls. There were a whole bunch of polls last time. Didn't work out," Obama said. "Because a whole bunch of folks stayed at home and got lazy and complacent. Not this time. Not in this election."

He went on to outline his belief that voting is the only remedy to right the wrongs of the Trump administration.

"In the end, Pennsylvania, that's what voting is about. Making things better, not making things perfect. But putting us on track so that, a generation from now, we can look back and say 'things got better starting now,'" Obama said. "Voting is about using the power we have and pooling it together to get a government that's more concerned and more responsive and more focused on you and your lives."

"I'm asking you to believe in Joe's ability, in Kamala's ability, to lead this country out of these dark times and help us build it back better because we can't abandon those who are hurting right now," he added.

Obama left the stage to Bruce Springsteen's "Land of Hope and Dreams" and put back on his mask which read "vote."

"Honk if you're fired up. Honk if you're ready to go," Obama said to blaring horns as he closed out the rally. "Are you fired up? Are you ready to go? Let's go make it happen. I love you, Philadelphia."

It was Obama's most critical speech of Trump yet.

-ABC News' Molly Nagle and John Verhovek

Former President Barack Obama arrived at a drive-in rally at Citizens Bank Park, home of the Philadelphia Phillies, to encourage early voting and emphasize down-ballot races in the battleground state. 

"Man, it is good to be back in Pennsylvania," Obama said in his first day of in-person campaigning for Biden. He immediately took a swipe at Trump, speaking to his rally in Erie Wednesday night in which Trump delivered a shorter-than-usual speech before urging voters to turnout early. 

"Apparently he complained about having to travel here. Then he cut the event short. Poor guy. I don't feel that way. I love coming to Pennsylvania," Obama said. "You guys delivered for me twice, and I am back here tonight to ask you to deliver the White House for Joe Biden and Kamala Harris."

Obama went on to criticize Trump's leadership, hitting the administration's attacks against the Affordable Care Act without having a replacement health care plan and what he called its mishandling of the coronavirus pandemic.

"Presidents up for re-election usually ask if the country is better off than it was four years ago. I'll tell you one thing, four years ago, you'd be tailgating here at the LINC instead of watching a speech from your cars," Obama said. 

"Donald Trump isn't suddenly going to protect all of us. He can't even take the basic steps to protect himself," he added.

The former president weaved insults of the president in with compliments of his former vice president.

"Now, he did inherit the longest streak of job growth in America, but just like everything else he inherited, he messed it up," Obama said. "Joe sees this moment not just as a chance to get back to where we were but to finally make long overdue changes so that our economy actually makes life a little easier for everybody." 

Obama's remarks were met with honks of approval as roughly 200 cars sat parked in a semicircle around the stage. Several attendees moved to sit on top of and around their cars to get a better view of the stage.

Prior to the event, Obama also made a brief stop at a community organizer event, where Biden-Harris supporters were handing out signs, buttons and hand sanitizers to a local North Philadelphia neighborhood.

President Trump continued to complain about Thursday night's debate, saying it's "very unfair" that the candidates' mics will be muted at points, when he spoke briefly to reporters as he departed the White House Wednesday on his way to North Carolina for another campaign rally.

"I think the mute is very unfair, and I think it's very bad they're not talking about foreign affairs, they're supposed to be talking about foreign affairs, and I think the anchor is a very biased person -- her parents are very biased -- but that's my life," Trump said. 

Asked about his preparations for the debate, the president said, "I do prep, I do prep" but did not elaborate.

-ABC News' Jordyn Phelps

Ahead of this evening’s drive-in rally, Obama made his campaign debut at a roundtable with Black community leaders in North Philadelphia to talk about what’s at stake in this election and encourage voter turnout. 

"The answer for young people, when I talk to them, is not that voting makes everything perfect, it's that it makes things better,” Obama said, wearing a mask while he spoke.

"The government’s us, of, by, and for the people. It wasn’t always for all of us. But the way it’s designed, it works based on who's at the table. And if you do not vote, you are not at the table," Obama said. "If you're at the table, then you're part of the solution."

"I really want to emphasize to young people as much as possible, look, in ‘08 when I was elected, we had the highest African American turnout in history. But it was still only about 60%. When people say voting doesn't make a difference, we’ve never tried what it would look like if it was 80% voting or 90% voting," he added.

Black voters remain an overwhelmingly Democratic-leaning constituency, but a notable reduction in their support could still be a problem for Biden, according to an analysis from ABC's partners at FiveThirtyEight. Older Black voters look as if they’ll vote for Biden by margins similar to Clinton’s in 2016, while Trump’s support among young Black voters has jumped from around 10% in 2016 to 21% in UCLA Nationscape’s polling.