We start with major developments in the race for the White House. President Biden is facing a growing campaign crisis, but tonight, showing no sign he is preparing to end his re-election run. Today in Wisconsin, the President saying, despite some Democrats trying to push him out, he's staying in the race. But tonight, it appears his support is eroding further among elected leaders. The Washington Post reports that key Senator Mark Warner of Virginia, is telling other Democrats that Mr. Biden Biden can no longer remain in the race. And Warner is trying to put together a group of Democratic senators to ask the President to bow out. Warner's spokesperson not confirming or denying that report. Also, tonight, the President is speaking about the issue in a primetime interview. Plus, he's planning a press conference next week as some Democrats demand he act quickly to show he has the mental fitness to continue this campaign. It's where we start tonight with Gabe Gutieras in Wisconsin.

With his candidacy hanging in the balance, tonight, President Biden looking for a lifeline in Battleground, Wisconsin, eight days after that disastrous debate.

Can't say it's my best performance. But ever since then, there's been a lot of speculation. What's Joe going to do? Is he going to stay in the race? Here's my answer. I am running and going to win again.

The President speaking with a teleprompter at a rally in Madison, addressing concerns about his age head on.

You think I'm too old to Donald Trump?

No. Pressure has been mounting on the 81-year-old Commander-in-Chief. While some anxious Congressional Democrats have called for him to step aside, others are weighing their options. Virginia Senator Mark Warner now organizing a group of his colleagues to meet to discuss what they believe the path forward for the President should be.

Mark Warner, by I said, is the only one considering that.

Big money donors also threatening to yank their cash from the campaign.

They're trying to push me out on the race. No. Well, Let me say this as clearly as I can. I'm staying in a race.

And in an exclusive interview with ABC News' George Stefanopoulos, late today reiterating his debate performance was because he wasn't feeling well.

But your friend Nancy Polosi actually framed the question that I think is on the minds of millions of Americans. Was this a bad episode or the sign of a more serious condition?

It was a bad episode. No indication of any serious condition. I was exhausted. I didn't listen to my instincts in terms of preparing. It was a bad night.

You say you were exhausted, and I know you said that before as well, and you did have a tough month, but you came home from Europe about 11 or 12 days before the debate, spent six days in Camp David. Why wasn't that enough rest time, enough recovery time?

Because I was sick. I was feeling terrible. Matter of fact, the docs with me, I asked them if they did a COVID test because they were trying to figure out what was wrong. They did a test to see whether or not I had some infection, a virus. I didn't. I just had a really bad cold.

Nervous supporters, as well as his critics, now scrutinizing his every word, including this stumble at last night's July fourth celebration.

I probably shooting this area, right?

Meeting with Democratic governors this week, two sources tell NBC News the President suggested he'd like his staff to limit his events after 8:00 PM so he can get more rest. One of the governors he met with, Maura Healey of Massachusetts, is now urging President to carefully evaluate whether to stay in the race. Nbc news is also reporting that some Democrats say the President's debate performance was not an anomaly. One Democratic Senator who declined to speak publicly, telling us the country saw what those of us who have had personal interactions with him have all known for the last two and a half years. To counter that narrative, today, the Biden campaign announcing an aggressive travel schedule and $50 million paid media blitz to reach voters. Do you think this It was just a one-night problem? I understand the concern, but I think in the long run, he'll prove people wrong. How typical was it to see that debate performance?

It was very difficult. In my mind, I was making all the excuses that a lot of Biden fans were making. But in the end, it's more what the American can't think. That's what scares me. I think he can do it.

Gabe joins us live now. Gabe, there is new reporting tonight on House Democratic leader, Hakeem Jeffrey's and his plan?

Yes, Tom. Multiple sources tell NBC News that leader Jeffreys is convening a virtual meeting on Sunday with Democratic Committee ranking members, and that it's expected to focus on President Biden as he faces calls to step aside. Tom?

Gabe Gutierish leading us off tonight. Gabe, thank you.

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