TUCSON, Ariz. (AP) — An angry President Donald Trump came out swinging Monday against Dr. Anthony Fauci, the press and polls that show him trailing Democrat Joe Biden in key battleground states in a disjointed closing message two weeks out from Election Day.

On the third day of a western campaign swing, Trump was facing intense pressure to turn around his campaign, hoping for the type of last-minute surge that gave him a come-from-behind victory four years ago. But his inconsistent message, another rise in virus cases and his attacks on experts like Fauci could undermine his final efforts to appeal to voters outside his most loyal base.

“I’m not running scared," Trump told reporters before taking off for Tucson, Arizona, for his fifth rally in three days. "I think I’m running angry. I’m running happy and I’m running very content 'cause I’ve done a great job.”

His aggressive travel comes as Trump plays defense in states he won four years ago, though the president insisted he was confident as he executed a packed schedule despite the pandemic.

“We’re going to win," he told campaign staff on a morning conference call from Las Vegas. He went on to acknowledge that he "wouldn’t have told you that maybe two or three weeks ago," referring to the days when he was hospitalized with COVID-19. But he said he felt better now than at any point in 2016. “We’re in the best shape we’ve ever been,” he said.

Seeking to shore up the morale of his staff amid growing private concerns that he is running out of time to make up lost ground, Trump blasted his government's own scientific experts as too negative, even as his handling of the pandemic that has killed nearly 220,000 Americans remains a central issue to voters.

“People are tired of hearing Fauci and all these idiots," Trump said of the government's top infectious disease expert. “Every time he goes on television, there’s always a bomb. But there’s a bigger bomb if you fire him. But Fauci’s a disaster."

At a rally in Prescott, Arizona, Trump assailed Biden for pledging to heed the advice of scientific experts, saying dismissively that his rival “wants to listen to Dr. Fauci."

The doctor is both respected and popular, and Trump's rejection of scientific advice on the pandemic has already drawn bipartisan condemnation.

At his rally, Trump also ramped up his attacks on the news media, singling out NBC's Kristen Welker, the moderator of the next presidential debate, as well as CNN for aggressively covering a pandemic that is now infecting tens of thousands of Americans every day.

Fauci, in an interview with CBS's “60 Minutes” that aired Sunday, said he was not surprised that Trump contracted the virus after he held a series of large events with few face coverings.

“I was worried that he was going to get sick when I saw him in a completely precarious situation of crowded, no separation between people, and almost nobody wearing a mask,” Fauci said of the president.

Biden was off the campaign trail Monday, but his campaign praised Fauci and criticized Trump for “reckless and negligent leadership” that "threatens to put more lives at risk.”

“Trump’s closing message in the final days of the 2020 race is to publicly mock Joe Biden for trusting science and to call Dr. Fauci, the leading public health official on COVID-19, a ‘disaster’ and other public health officials ‘idiots,'" the campaign said.

Monday's professed confidence in victory stood in contrast to some of Trump's other public comments in recent days reflecting on the prospect that he could lose.

“Could you imagine if I lose my whole life? What am I going to do?" he asked a rally crowd last week in Macon, Georgia. "I’m not going to feel so good. Maybe I’ll have to leave the country. I don’t know.”

Biden, meanwhile, was in Delaware for several days of preparation ahead of Thursday's final presidential debate. His running mate, California Sen. Kamala Harris, returned to the campaign trail after several days in Washington after a close adviser tested positive for the coronavirus.

Late Monday, the nonpartisan Commission on Presidential Debates announced that Trump and Biden will each have his microphone cut off in Thursday’s debate while his rival delivers his opening two-minute answer to each of the six debate topics.

The rule changes come three weeks after a chaotic opening faceoff between the two presidential contenders that featured frequent interruptions — most often by Trump. The open discussion portion of the debate will not feature a mute button, but interruptions by either candidate will count toward their time.

The commission has faced pressure from the Trump campaign to avoid changing the rules, while Biden’s team was hoping for a more ordered debate. In a statement, the commission said it “had determined that it is appropriate to adopt measures intended to promote adherence to agreed upon rules and inappropriate to make changes to those rules.”

Trump's campaign said he would participate in the debate despite his concerns about the new rule.

“I just think it’s very unfair,” Trump told reporters aboard Air Force One as he returned from Arizona. “I will participate but it’s very unfair that they changed the topics and it’s very unfair that again, we have an anchor who’s totally biased.”

In addition to public polling that indicates Biden has an edge, the former vice president enjoys another considerable advantage: money.

Over the past four months, Biden has raised over $1 billion, a massive amount of money that has significantly eclipsed Trump's once-overwhelming cash advantage.

That's become apparent in advertising, where Biden and his Democratic allies are on pace to spend twice as much as Trump and the Republicans in the closing days of the race, according to data from the ad tracking firm Kantar/CMAG.

“We have more than sufficient air cover, almost three times as much as 2016," said Trump campaign manager Bill Stepien, who insisted Trump has the advantage with the campaign's field staff and data targeting.

Though Trump has pulled back from advertising in Midwestern states that secured his 2016 win, he's invested heavily elsewhere, including North Carolina, where he is on pace to slightly outspend Biden.

Concerns about a possible loss to Biden that have been spilling into the open in recent days have been percolating behind the scenes at the Trump campaign. Trump himself has alternated between disbelief and anger at the idea that he could lose to a candidate whom he views as washed up and incompetent, according to three campaign and White House officials not authorized to speak publicly about private conversations.

Trump has directed anger at press coverage but also has vented about his chief of staff, Mark Meadows, whom he blames for mishandling his hospitalization for the virus and COVID relief talks.

He has asked some of his closest advisers if a campaign shakeup was needed, according to the officials. The president was encouraged to hold off on any moves so close to Election Day.

Meanwhile, aides have started privately wondering whether or not Trump's campaign rallies, which have helped define American politics for the last five years, were in their final days.

In recent weeks, meanwhile, some White House staff offices have also tried to rotate in aides who have never flown on Air Force One or have done so infrequently so they can do so before Election Day.

___ Miller reported from Washington. Associated Press writers Will Weissert in Wilmington, Delaware, Jonathan Lemire in New York and Brian Slodysko in Washington contributed to this report.