As House Republicans kick off an impeachment inquiry against President Biden, the White House is executing a long-planned strategy to meet politics with politics.

Forget the weighty legal arguments over the meaning of high crimes and misdemeanors or the constitutional history of the removal process. Mr. Biden’s defense team has chosen to take on the Republican threat by convincing Americans that it is nothing more than base partisanship driven by a radical opposition.

A day after Speaker Kevin McCarthy announced the inquiry in response to pressure from his right wing, the White House and its allies went on the offensive Wednesday, dismissing the allegations against the president as baseless and debunked, attacking the investigators for distorting the evidence, issuing fund-raising appeals to financial supporters and pressuring the news media to frame the conflict on their terms.

If it feels more like a political campaign than a serious legal proceeding, that is because at this point it is, at least as the White House sees it and would like others to. In the first 24 hours of their inquiry, the House Republicans made no new requests for documents, issued no new subpoenas, demanded no new testimony and laid out no potential articles of impeachment. Instead, they went to the cameras to call Mr. Biden a liar and a crook, so Mr. Biden’s defenders went to the cameras to return fire.

“We’re battling it out in the court of public opinion at this stage because that’s all that McCarthy has done, the theater of impeachment,” Ian Sams, a senior adviser to the White House Counsel’s Office who is leading the communications campaign, said in an interview after a day in which he made the rounds on television news shows.

At a campaign reception in McLean, Va., on Wednesday night, the president noted that Republicans had been pushing for an impeachment inquiry from the beginning of his administration.

“I don’t know quite why, but they just knew they wanted to impeach me,” he said. “And now, the best I can tell, they want to impeach me because they want to shut down the government.” He added: “I get up every day, not a joke, not focused on impeachment. I’ve got a job to do.”

The Republican investigation so far has not produced concrete evidence of a crime by the president, as even some Republicans have conceded. Testimony has suggested that his son, Hunter Biden, traded on the family name to secure millions of dollars in business, including from foreign firms, and that he put his father on the phone sometimes with would-be clients to impress them.

But Hunter Biden’s former business partner testified that the future president engaged only in idle chitchat, not business, during those calls. No evidence has been produced indicating that Mr. Biden himself received any money from his son’s business dealings or used his power as vice president to benefit Hunter’s financial interests.

For the Biden team, the mission now is to discredit the impeachment inquiry among independent voters and wayward Democrats before it reaches a crescendo. It is a strategy employed in the past by other presidents targeted for impeachment, Bill Clinton and Donald J. Trump.

The Republicans so far have helped Mr. Biden’s effort, often speaking about the investigations into the president’s family in starkly political terms. Mr. Trump, who is seeking a rematch of his 2020 loss to Mr. Biden, has loudly pushed fellow Republicans to impeach because “THEY DID IT TO US!”, as he wrote on social media.

Representative Marjorie Taylor Greene, Republican of Georgia, who was among those who pushed Mr. McCarthy into opening an inquiry at Mr. Trump’s behest, made clear that the goal was to damage the incumbent president. By her own account, she said she told Mr. Trump during a dinner on Sunday at his private club in Bedminster, N.J., that she hoped to make an impeachment inquiry “long and excruciatingly painful for Joe Biden.”

But some Democrats said the White House had let the investigations get out of hand with flat denials that then did not stand up when new information became available.

Julian Epstein, who was the chief counsel for Democrats on the House Judiciary Committee during the Clinton impeachment, said the president “seems to have clearly been aware of, if not actively enabling, his son’s efforts to monetize the vice president’s office” even if he did not profit personally or use his official power to help.

“Overall, this has not been handled well by the White House,” Mr. Epstein said. “The team there has violated the cardinal sin of investigations — allowing new information to trickle out continuously and while being stuck in stale Baghdad Bob-like ‘no evidence’ denials,” he added, referring to an Iraqi official during and after the U.S.-led invasion in 2003, who denied the reality of the war in his country that was visible on television screens.

The White House strategy calls for the president to focus on policy issues while leaving the battle with Republicans to his staff and also highlighting the contrast between the president and his foes, much as Mr. Clinton did 25 years ago. “We think they should work with us on legitimate issues — things that actually matter to the American people,” Karine Jean-Pierre, the White House press secretary, told reporters.

Neil Eggleston, who was a White House lawyer for Mr. Clinton, said it was important to draw the contrast. “The White House needs to continue to execute and be presidential,” he said. “It is too easy for the entire team to focus on responding to every new claim by the House Republicans. Distraction is the game here, and the White House should refuse to play.”

Polls show that the inquiry is viewed through a political lens by much of the public. A YouGov survey conducted on Wednesday found that only 28 percent of American adults believe that the impeachment inquiry is a serious attempt to find out what really happened while 41 percent think it is a politically motivated attempt to embarrass Mr. Biden. Another 16 percent think it is equally motivated by both. Altogether, 45 percent supported opening the inquiry while 40 percent opposed it, largely along party lines.

That reflects a change in the politics of impeachment over the half century since President Richard M. Nixon resigned in 1974 rather than face near-certain impeachment in the House and likely conviction in the Senate. At the time, House Democrats leading the inquiry aimed to win over Republicans to make it a bipartisan effort that would win favor with the public, and succeeded with a significant number of the president’s own party.

When House Republicans pursued Mr. Clinton in 1998, there was still at least the possibility of bipartisanship. When the House voted to open an inquiry against him for perjury and obstruction of justice stemming from his attempt to thwart a sexual harassment lawsuit against him, 31 Democrats voted to investigate, though only five ultimately voted for impeachment once the inquiry was complete.

By the time House Democrats opened the first impeachment inquiry into Mr. Trump in 2019 because of his efforts to pressure Ukraine to open an investigation into Mr. Biden, no Republicans voted to authorize the investigation and none voted to impeach. The second impeachment against Mr. Trump in the aftermath of the Jan. 6, 2021, attack on the Capitol, by contrast, drew 10 votes by Republicans to charge him with high crimes.

At this point, there is no sense that any member of Mr. Biden’s party in Congress thinks an impeachment inquiry is justified, and indeed quite a few House and Senate Republicans have said they do not think so either. As a result, Mr. McCarthy likely could not muster the support of a House majority to open an inquiry, leading him to do it on his own authority even though he had said just this month that any impeachment inquiry would have to be voted on by members on the House floor.

Republican investigators seemed unprepared for Mr. McCarthy’s move and did not have a plan of action for the hours afterward. Representative James R. Comer, Republican of Kentucky and chairman of the House Oversight Committee, who has been investigating the Biden family for months, said on Wednesday that he would push for bank records for Hunter Biden and for James Biden, the president’s brother.

“We’re headed to court, more than likely,” Mr. Comer told the conservative site Newsmax. “We’ve requested bank records from Hunter Biden and Jim Biden early on and obviously we never got a response back. We will re-request those this week; if they do not comply with our request, then we will subpoena and no doubt, undoubtedly, head to court.”

Abbe Lowell, a lawyer for Hunter Biden, fired back in a letter to Mr. Comer, accusing him of dissembling. Mr. Lowell noted that while he criticized the request for bank records, he had offered to sit down with Mr. Comer “to see whether Mr. Biden has information that may inform some legitimate legislative purpose and be helpful to the committee,” as he wrote on Feb. 9.

“You never responded to that offer,” Mr. Lowell wrote on Wednesday.

The bank records may test Mr. Biden’s approach to the inquiry. During his first impeachment, Mr. Trump refused to cooperate with requests for information and subpoenas, deeming the inquiry illegitimate, in part because it was not authorized at first by a House vote.

Mr. Biden’s aides have said they have been cooperating with requests for information during the investigations so far but would not commit to how they would handle future requests since they have not received them. Mr. Biden could cite Mr. Trump’s precedent — a stiff-arm approach supported by House Republicans at the time — and refuse to press his family to release bank records, but it could be seen as contrary to his longstanding support for restoring institutional norms shattered by Mr. Trump.

The White House ceded no ground on Wednesday, sending out a memo to news media organizations pressing them to report on the impeachment inquiry in terms favorable to Mr. Biden, an old-fashioned effort to “work the refs,” as the Washington saying goes. “It’s Time For The Media To Do More To Scrutinize House Republicans’ Demonstrably False Claims That They’re Basing Impeachment Stunt On,” the memo said, attaching a 14-page appendix rebutting each of the Republican allegations.

The Biden team likewise turned the inquiry into a fund-raising tool. A solicitation email sent in the name of Vice President Kamala Harris appealed to supporters to send money to counter impeachment. “It’s clear: They’re going to throw everything they have at Joe, because they know they can’t run against our record,” Ms. Harris said in the email. “If you’re waiting for a moment to show your support for him, trust me when I say: This is it.”

Zach Montague contributed reporting.