Joe Biden Joe BidenBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Democratic groups using Bloomberg money to launch M in Spanish language ads in Florida Harris faces pivotal moment with Supreme Court battle MORE’s presidential campaign on Tuesday sent out a fundraising email to supporters citing President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE’s repeated social media attacks against the former vice president, saying that the recent barrage is evidence that the White House fears a Biden challenge in 2020.

“He retweeted over 60 anti-Biden tweets in less than an hour. This is unprecedented. He’s never gone after a candidate like this before. It’s clear that Donald Trump fears Joe and wants to derail his candidacy,” the campaign said.

ADVERTISEMENT

“The attacks have already started and we need to be able to fight back. That means raising 25,000 grassroots donations before our mid-month deadline next week. If we are going to get there, we need every last supporter to step up,” it added.

Biden, who officially launched his presidential campaign in April after months of speculation, has quickly emerged as the primary pack’s pacesetter, emerging at the top of several national and statewide polls and raking in a staggering $6.3 million within the campaign’s first 24 hours.

Officials have privately told several media outlets that Trump views Biden as one of his biggest threats among the 22 current Democratic candidates because of his appeal to white working-class voters in the Rust Belt who historically voted Democrat but flipped in 2016.

The president has gone on a tear on social media, retweeting criticisms of Biden and launching his own broadsides, dubbing him “Sleepy Joe.”

“The Media (Fake News) is pushing Sleepy Joe hard. Funny, I’m only here because of Biden & Obama. They didn’t do the job and now you have Trump, who is getting it done - big time!” Trump tweeted last month.

The Media (Fake News) is pushing Sleepy Joe hard. Funny, I’m only here because of Biden & Obama. They didn’t do the job and now you have Trump, who is getting it done - big time! — Donald J. Trump (@realDonaldTrump) April 29, 2019

Trump seemed to be especially irked after Biden gained the endorsement of the influential International Association of Fire Fighters, the union representing firefighters.

“The Dues Sucking firefighters leadership will always support Democrats, even though the membership wants me. Some things never change!” he tweeted after the endorsement.

The Dues Sucking firefighters leadership will always support Democrats, even though the membership wants me. Some things never change! — Donald J. Trump (@realDonaldTrump) April 29, 2019

Trump retweeted nearly 60 messages Wednesday morning echoing his claim that while the union leadership backed Biden, the rank-and-file members supported him.