WASHINGTON - President Donald Trump and his campaign team are grappling with how to resuscitate his imperiled reelection effort amid a wave of polling that shows him trailing presumptive Democratic nominee Joe Biden and losing traction even among core constituencies.

Some Trump advisers and allies are privately pushing for sweeping changes to the campaign, including the idea of a major staff shake-up and trying to convince the president to be more disciplined in his message and behavior.

But so far, the campaign has settled only on incremental changes - such as hiring and elevating several operatives who worked on Trump's upset victory in 2016 - and has yet to settle on a clear message for his reelection. Campaign officials and other advisers are also still struggling with how to best focus their attacks on Biden, which so far have been scattershot and have failed to curb his rise among voters.

And then there's Trump himself, who has derailed his team's desired themes on an almost daily basis - deploying racist rhetoric and mounting incendiary attacks on critics amid a surging coronavirus pandemic, an economic crisis and roiling protests over police brutality.

Numerous national polls show Trump losing significant ground with seniors and among white voters, including those with and without four-year college degrees. He has also slipped among white evangelical voters. According to new New York Times/Siena College polls, Trump is at least slightly behind Biden in six states that he won in 2016 and are pivotal to his reelection path - including Michigan, Pennsylvania and Wisconsin, where he trails by double digits.

"You can't win with these numbers. They're atrocious numbers," said Edward Rollins, co-chairman of the pro-Trump super PAC Great America and the former campaign manager for Ronald Reagan's 1984 reelection campaign.

"The president must straighten his campaign out and convey to the American people that he can move forward and lead," Rollins said. "He's got to go out and add 10 points pretty quick. If he can do that, he'll win. If not, Biden is sitting there as the alternative."

Trump's advisers and allies have grown frustrated with some of the president's incendiary and divisive behavior and comments in recent weeks and are dismayed by the polls, including some of their own internal surveys that also show him losing to Biden. The president also came under fire for a June 20 rally in Tulsa that failed to attract much of a crowd even as the campaign downplayed coronavirus distancing guidelines.

But many Trump allies remain deeply skeptical of the public polling - pointing to 2016 polls in key states that underestimated Trump's support - and say the internal polling and modeling that they're sharing with the president is less grim than the public surveys. Officials with the campaign and the Republican Party also asserted that they have seen no serious erosion in Trump's political base.

"Over the past four months, the president's support among Republican voters has ranged between 90 and 94% consistently," said Tony Fabrizio, the campaign's chief pollster, referring to the campaign's internal polls. "As of our most recently polling, it stands at 94%."

Fabrizio added that any erosion is among independent voters, who usually swing back and forth between the two major-party nominees.

Trump has polled advisers on whether he should make changes to the campaign, and several White House and campaign officials said there were ongoing discussions on how to improve the president's political standing.

The president has responded to the turmoil by doubling down on his nativist and base instincts, attempting to rally his core supporters through controversial and racially tinged comments and tweets.

The latest example came Sunday, when Trump retweeted a video that included a supporter proclaiming "white power" in response to counterprotesters and calling his backers in Florida retirement community where the demonstration occurred "great people." Trump later deleted the tweet, and a White House spokesman said the president had not heard the "white power" shout.

He has twice referred to the deadly coronavirus, which originated in China, derisively as the "kung flu." In an interview with the Christian Broadcasting Network on Monday, he baselessly accused former President Barack Obama of "treason." And he has dismissed protesters demanding racial justice - who took to the streets after the killing of George Floyd in police custody - as "hoodlums," "thugs," and even "terrorists," promising "retribution" in an interview with Fox News's Sean Hannity on Thursday night.

Advisers, meanwhile, are frustrated with the president's tendency to portray himself as the victim, and have urged him to stop the public displays of self-pity.

"If the election was today, we are in big trouble," according to one person close to Trump, who like others spoke on the condition of anonymity to share a candid assessment. "Thankfully it is not."

Former New Jersey Gov. Chris Christie, a Republican, warned on ABC News's "This Week" on Sunday that if Trump "doesn't change course both in terms of the substance of what he's discussing and the way that he approaches the American people, then he will lose."

"The trend is obvious," Christie said. "The trend is moving towards Joe Biden when Joe Biden hasn't said a word. Joe Biden's hiding in the basement and not saying anything. No discredit to the vice president - if you're winning without doing anything, why do anything?"

An urgent task for Trump and his team, advisers say, is to find a way to negatively define Biden - transforming the election into a choice between the two men, rather than a referendum on Trump.

Trump has recently been asking advisers whether he should stick with his current nickname for Biden - "Sleepy Joe" - or try to coin another moniker, such as "Swampy Joe" or "Creepy Joe." The president is not convinced that "Sleepy Joe" is particularly damaging, and some of his advisers agree and have urged him to stop using the nickname. In a tweet on Sunday, Trump tried out yet another variant: "Corrupt Joe."

Some advisers are also concerned that the campaign's attacks on Biden's mental acuity might alienate older voters, and that it also inadvertently sets a low bar for gauging Biden's performance.

Trump's team has deployed the hashtag #HidenBiden, intended to highlight that it's been nearly three months since Biden has held a regular news conference and pressure him into more public appearances. In addition, the campaign plans to deploy a theme casting Trump as a builder - a former real estate developer who created jobs and a strong economy before the coronavirus pandemic and who has pushed ahead with construction of a new wall at the southern border.

"I think when it comes down to a binary choice, and they look at Biden, the natural question is going to be: How can you run as a change agent and a change candidate when you spent 50 years in Washington?" said Ronna McDaniel, chair of the Republican National Committee.

Trump's team had initially fashioned much of the campaign around the strong economy, but now is pushing a "renew, restore, rebuild" theme, hoping to stress that Trump is best positioned to return the country to economic prosperity.

The campaign has undergone staff changes in recent weeks intended to right the ship, including the addition of Jason Miller, a former senior adviser on the 2016 campaign who has a good relationship with Trump.

A comparison of recent national polls to 2016 exit polls and a Pew survey of confirmed voters finds that Trump has lost significant ground among whites. He fares slightly better among nonwhites than he did four years ago, though not enough to counterbalance these other losses.

In 2016, Trump won whites by an average of 18 points across two surveys of 2016 voters; surveys since late May averaged by The Washington Post show him leading by five percentage points. Among whites without college degrees, Trump won the group by 37 points over Hillary Clinton in 2016, but recent polls show him dropping 15 points, to a 22-point advantage over Biden. And although Trump won seniors by eight points in 2016, he trails Biden by five points on average in recent national polls.

Juan Peñalosa, the executive director of the Florida Democratic Party, said seniors are both worried about the economy and angry about the novel coronavirus. "They are angry because they feel as if they are prisoners in their own home and they can't see their grandchildren," Peñalosa said. "And they blame Trump for this."

Trump campaign manager Brad Parscale rejected the validity of public polling and blamed the media for many of the president's current woes. "We know we are in solid shape in all of our key states, and no amount of fake, narrative-setting media polls can ever change that," Parscale said in an email.

A senior White House official said that although Biden outraised Trump for the first time in May, the Trump campaign still outmatches Biden with $265 million cash on hand.

White House and campaign advisers are homing in on Arizona, Florida, North Carolina and Wisconsin as states where they must win - believing that they are in good shape in Ohio, and that Michigan and Pennsylvania will be far more difficult this time. In a clear sign of worry, the campaign has purchased ad time in Georgia, a longtime GOP stronghold.

Some of the president's advisers have told him that his hard-edge messaging has hurt him in recent weeks, showing him polling from swing states where he is trailing. And they have urged him to a run a general election strategy that appeals to a broader swath of voters, rather than a primary strategy that caters to his already energized base, said one person familiar with the encouragement.

Two people who spoke with Trump this past week said he is arguing that groups defacing and tearing down monuments and statues will ultimately benefit him politically because the public will appreciate his harsh stance and "law and order" message. The president has also told his political advisers that there is more enthusiasm for him than for Biden, and he doesn't believe the polls, saying "10 points" should be added to his numbers.

"The campaign is hyper-focused on playing to the base - I think it's a mistake," said Chris Ruddy, chief executive of the conservative Newsmax Media and a longtime Trump confidant. "Politics are about addition, not subtraction. In this environment, the president has to do a lot of plus plus plus addition signs right now with every group that he possibly can."

With Trump struggling to cope with numerous crises, many in both parties believe Trump's standard playbook may not work as it did in 2016.

"In conservative places like Ohio, you really wonder if what Trump is selling will work again," said former Ohio Gov. Ted Strickland, a Democrat. "NASCAR is banning the Confederate flag at races. Military leaders are speaking out against him. If the NFL starts again, you'll see a lot of people kneeling. This is not the same country that it was in 2016."

Speaking Thursday in Pennsylvania, Biden similarly took aim at Trump, saying the president is handling the coronavirus "like a child who can't believe this has happened to him."

"All his whining and self-pity," Biden said. "This pandemic didn't happen to him. It happened to all of us. And his job isn't to whine about it. His job is to do something about it, to lead."

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The Washington Post's Scott Clement and Michael Scherer contributed to this report.