Biden's aggressive campaign strategy involves swing-state stops and jabs at Trump

As President Joe Biden ramps up an aggressive reelection campaign schedule -- while still facing mediocre early polling and poor approval ratings -- he is targeting swing states, fundraising and attacking former President Donald Trump in mocking jabs that mimic some of his rival's own language.

In the initial phase of a long general election fight to November, Biden has traveled to every battleground state in the month since his State of the Union address with visits to Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin.

Trump has held just two campaign rallies in Ohio and Georgia in the same amount of time, in part because his schedule was complicated by his legal issues (he denies all wrongdoing).

He went back out on the trail on Tuesday, in Michigan and Wisconsin, where he railed against Biden's "border bloodbath" among other attacks.

The Biden campaign has seized on the differences in their recent scheduling, flipping a criticism back on Trump -- about Trump's absences -- that Trump frequently used against Biden during the 2020 campaign amid the COVID-19 pandemic.

"His campaign can't raise money, he is uninterested in campaigning outside his country club, and every time he opens his mouth, he pushes moderate and suburban voters away with his dangerous agenda," Biden campaign spokesperson James Singer in a statement last week after Trump appeared in New York court for a hearing related to his hush money trial, in which he has pleaded not guilty.

Asked for a response to the attacks about his campaign approach, Trump's team shot back by arguing that Biden's incompetence makes him unfit for the job.

The Trump campaign also boasted in a statement to The Hill on Tuesday that "we have the message, the operation, and the money to propel President Trump to victory."

Trump adviser Chris LaCivita touted Trump's performance in winning the GOP nomination, too.

"The Trump campaign, after shattering records in primary and caucus wins in both turnout and margin across the country, has locked up the nomination in one of the fastest timelines in modern day political history," LaCivita said, in part.

In addition to a more bustling schedule, Biden has a campaign cash advantage, having been able to jointly fundraise with the Democratic National Committee. He ended last month with more than twice as much money on hand as Trump, according to campaign financial disclosures.

The Biden campaign has $71 million on hand, according to Federal Election Commission filings; Trump, who up until March hasn't been able to fundraise with the Republican National Committee because of the contested GOP primary, has $33.5 million, according to the FEC filings.

Former President Barack Obama joined Biden for a "record-breaking" fundraiser on Thursday in New York City, bringing in more money in one night than Trump did last month, his campaign claimed.

That event followed a visit from Obama to the Biden White House last week, where they taped a video to tout 14 years of the Affordable Care Act, among other fundraising content.

Trump soon expects to lap Biden in fundraising in one regard, however.

He and the Republican Party are throwing a joint event in Palm Beach, Florida, this week that has raised at least $33 million, organizers say.

That haul, which cannot be verified until campaign disclosure filings come out, would likely outraise Biden's New York fundraiser.

In sharpening attacks on Trump, the Biden campaign also says Trump has other problems beyond money -- including that his once-loyal No. 2, former Vice President Mike Pence, declined to endorse him, citing differences beyond the Capitol attack on Jan. 6.

"Those who worked with Donald Trump at the most senior levels of his administration believe he is too dangerous, too selfish, and too extreme to ever lead our country again -- we agree," said Biden spokesperson Ammar Moussa in response to Pence's move to not endorse Trump.

Biden's reelection effort appears to be outpacing Trump in infrastructure as well. In preparation for the long fight ahead, Biden and Democrats have opened more than 100 coordinated offices in key battleground states, according to the campaign.

In North Carolina, a state Biden narrowly lost to Trump in 2020, Biden's campaign is opening 10 field offices after opening 44 offices in Wisconsin, 20 offices in Michigan and at least a dozen in Pennsylvania.

"We're ramping up campaign headquarters and field offices, hiring staff all across the country," Biden said in a call to grassroots donors last week, flanked by former Presidents Obama and Bill Clinton. "And before Trump and MAGA Republicans haven't even opened one office."

A Trump campaign spokesperson did not respond on Tuesday to questions about their amount of field offices.

'Take the gloves off'

Biden has ramped up some of his anti-Trump barbs in a way that is landing with some voters.

On Friday morning in New York, Biden offered what's become a recurring laugh line to the Victory Fund National Finance Committee Spring Retreat -- a daylong gathering at the InterContinental New York Barclay hotel with 175 top-dollar donors.

"I know not everyone is feeling the enthusiasm. Just the other day a guy came up to me and said, 'Mr. President, I'm being crushed by debt, I'm completely wiped out, I need some help.' I had to say, 'I'm sorry, Donald, I can't help you.'"

At a March fundraiser in Texas, Biden slammed Trump for infamously suggesting Americans might be able to ingest disinfectants and use light to combat COVID-19 early in the pandemic.

"He just kept getting worse. He told Americans, remember when he said inject bleach? I think he must have done it," he said.

Biden regularly jokes about his own age, which is frequent fodder for criticism by Republicans, but he also uses the topic to segue into an attack of Trump's ideas as being "old."

"I'd be happy to compare physical characteristics," Biden, who is 81, said at a fundraiser last week in North Carolina about Trump, who is 77. "Granted, I don't have his orange hair."

Voter Jerome Abron, a registered Democrat and manager of a Bojangles in Raleigh, North Carolina, said he is ready to see more of these types of attacks in public.

"I think he needs to take the gloves off," Abron said to ABC News last week. "Take the gloves off. Time to be aggressive."

However, when Biden speaks about how he sees Trump as a serious threat to American democracy, a charge that Trump denies, he often appears to show restraint -- wanting to say more, but stopping himself before finishing the thought.

Biden twice stopped himself from going further on Friday morning -- when telling donors about Trump embracing dictators and lamenting about his "old ideas."

"Talking about how Hitler did some good things -- I won't say it," Biden said at one point -- a reference to reports of comments Trump had made, according to his former chief of staff John Kelly.

Biden, a devout Catholic, said at another point: "There's a lot of focus these days on how old Trump and I are. Well ... I shouldn't say it. I won't say it. Not for the fact it was Good Friday, I might say it."

ABC News' Lalee Ibsa and Soorin Kim contributed to this report.