Biden, defiant in crisis, holds fiery rally in Wisconsin ahead of pivotal ABC News interview

President Joe Biden traveled to 2024 battleground Wisconsin on Friday for a closely-watched campaign rally and a critical interview with ABC News that could prove pivotal to his candidacy and presidency.

At the high-stakes event intended to reassure the state's Democratic voters he's up to the job after a rough debate performance last week, Biden energetically spoke about the policies his administration has implemented and the risks that another Trump presidency would bring.

And on concerns about his candidacy and fitness to serve, Biden was emphatic.

"Now you probably heard we had a little debate last week," Biden quipped. "Can't say it was my best performance. But ever since then, there's been a lot of speculation. What's Joe gonna do? Is he gonna stay in the race? Is he going to drop out? What's he going to do?"

"Well here's my answer. I am running and gonna win again," he said.

Biden's voice boomed through the Madison middle school where he spoke before a friendly crowd, who often broke on in cheers for "four more years."

His delivery on Friday -- which was aided by teleprompters -- was strong, particularly in comparison to last week's debate. Still, any stumbles by the 81-year-old are being viewed with the heightened scrutiny about his ability to lead for another term.

Biden was met with a large crowd outside the campaign event, some of whom were calling on him to step aside. One sign in the crowd read, "Save your legacy, drop out."

The week since the debate has been one of the most critical periods for Biden's presidency -- with many top Democrats continuing to watch him closely through the holiday weekend.

Biden is under growing pressure to publicly prove his mental and physical fitness -- by answering questions and making unscripted remarks -- and he'll get a high-stakes chance to do so when ABC anchor George Stephanopoulos speaks with him in Madison on Friday.

The first excerpts will air on "World News Tonight" and then the interview will be broadcast in its entirety in a prime-time ABC network special on Friday evening at 8 p.m. ET.

Watch: ABC News anchor George Stephanopoulos' exclusive first post-debate TV interview with President Joe Biden airs in its entirety in an ABC News prime-time special Friday, July 5, at 8 p.m. ET.

The president, too, has privately acknowledged that these few days are critical for his re-election prospects, sources familiar with conversations told ABC News earlier this week. While he still views himself as the best candidate to defeat Donald Trump, he signaled to one ally that he is keeping an "open mind" about his path forward.

Publicly, though, the White House rejects the notion that Biden is considering any path besides re-election, with White House press secretary Karine Jean-Pierre saying Thursday that Biden is "absolutely not" stepping down.

And meeting with Democratic governors at the White House Wednesday, a meeting scheduled after the debate for leaders to voice their concerns and hear directly from the president, Biden vowed to continue his presidential campaign, according to California Gov. Gavin Newsom.

One of more than 20 Democratic governors who met behind closed doors with Biden - virtually as well as in-person -- Newsom said Thursday while campaigning for Biden in Michigan, "I was really proud to be with Joe Biden last night. He started the meeting -- the first words out of his mouth: 'I'm all in'."

Another Democrat who's been speculated about as a possible replacement as the party's nominee, Michigan Gov. Gretchen Whitmer, posted, "Joe Biden is our nominee. He is in it to win it and I support him."

At the same time, though, more than a half dozen governors in the meeting expressed concern over the president's debate performance and the resulting fallout inside the party, two people familiar with the conversation told ABC News.

According to those people, one governor told Biden flat-out that people didn't think he was up to the task of running, and another asked him to lay out the path forward.

One person who attended the meeting described the conversation as "candid" and "blunt," saying the president was "engaged" and "focused."

Meanwhile, some congressional Democrats have gone public with their calls for Biden to step aside.

After Texas Rep. Lloyd Doggett on Tuesday became the first lawmaker to publicly say Biden should leave the race, another House Democrat -- Rep. Seth Moulton of Massachusetts -- said Thursday that Biden should withdraw.

Rep. Raúl M. Grijalva of Arizona also publicly urged Biden to leave the race, citing the "precarious" state of the president's campaign in an interview with The New York Times, and Rep. Marie Gluesenkamp Perez of Washington state told KATU she thinks Biden's performance last Thursday will cost him the election against Trump.

Democrats in leadership positions, however, have stayed in lockstep with the president, including former House Speaker Nancy Pelosi, Senate Majority Leader Chuck Schumer, House Minority Leader Hakeem Jeffries and Rep. Jim Clyburn of South Carolina, a key advisor to Biden who helped him to election in 2020.

ABC News' Fritz Farrow, Molly Nagle, Isabella Murray and Oren Oppenheim contributed to this report.