Hunter Biden, who goes on trial for tax evasion in September and could be sentenced to prison in October on firearms offenses, has in recent days emerged as a key adviser to his father on political strategy following the elder Biden’s disastrous performance in last week’s debate, according to multiple reports. 

According to NBC News, the first son has been a visible presence in the White House, stopping by unannounced as President Biden is meeting with staff about the presidential race. The New York Times reported this past weekend that the first had emerged as a forceful voice, along with his stepmother, first lady Jill Biden, urging his father to stay in the race. 

According to the NBC report, White House aides are asking themselves and each other: “What the hell is happening?” regarding the sudden intrusion of Biden, long a visible presence at White House social events such as state dinners and the Easter egg roll, into serious political meetings.

The White House press secretary, Karine Jean-Pierre, said on Tuesday in response to the NBC report that Biden only participated in one “speech prep” meeting with his father and senior advisors on Monday before the president addressed the media, without taking questions, about the Supreme Court’s presidential immunity decision. 

“The president is very close to his family. This is a holiday week,” Ms. Jean-Pierre said. “He’s close to his family, which is not unusual.”

This past weekend, Biden was present along with many other family members at Camp David for what the White House said was a pre-planned family gathering where the tight-knit Biden clan was to pose for the celebrity photographer Annie Leibovitz. It was during this post-debate gathering that, according to the Times, the first son and the first lady urged the president to stay in the race.

Biden was recently convicted on three felony charges related to his purchase of a firearm while addicted to drugs in 2018. Trump brought up the felony conviction during the Thursday debate, after the president pointed out that Trump was a convicted felon, leading Mr. Biden to go after his predecessor for “sleeping with a porn star” while his wife was pregnant and having “the morals of an alley cat.”

(Trump then responded, “I never had sex with a porn star.”)

Mr. Biden suffered a major defeat on Tuesday when the first House Democrat came forward to explicitly call on him to step down as the party’s presidential nominee. Congressman Lloyd Doggett, a longtime liberal House member from Austin, Texas, said he had hoped to be reassured by the president’s debate performance, but walked away only with fear that Trump would defeat him. 

“Our overriding consideration must be who has the best hope of saving our democracy from an authoritarian takeover by a criminal and his gang. Too much is at stake to risk a Trump victory,” Mr. Doggett said in a statement. “Much of his work has been transformational, he pledged to be transitional. He has the opportunity to encourage a new generation of leaders from whom a nominee can be chosen to unite our country through an open, democratic process.”

Democrats may have been heartened on Tuesday when a new CNN poll showed that Vice President Harris — the only person legally able to use the sizable Biden–Harris war chest — could actually be competitive in the 2024 race if she does become the nominee. The poll found that Mr. Biden trails behind Trump by six points, 43 percent to 49 percent, which is outside of the three-and-a-half point margin of error. Ms. Harris, on the other hand, is losing to Trump by just two points, 45 percent to 47 percent. Prior to this poll, Ms. Harris’s candidacy was largely considered a nonstarter by the Democratic establishment.

Three other candidates — Governor Whitmer, Governor Newsom, and the transportation secretary, Pete Buttigieg — are all more competitive than Mr. Biden in a hypothetical race with Trump than Mr. Biden, though less so than Ms. Harris.

The poll also showed that Democratic voters overwhelmingly believe — by a margin of 75 percent to 25 percent — that “someone else” would perform better as the presidential candidate than Mr. Biden. 

Even worse news came for the Biden campaign by Tuesday afternoon when a Democratic-aligned firm’s poll of battleground states was leaked to Puck News. The survey showed Trump gaining ground in reliably blue states like New Mexico, Virginia, and New Hampshire. Mr. Biden leads in Colorado by less than two points, and in Minnesota by less than half a point. If the poll turns out to be accurate, Mr. Biden could well end up with fewer than 200 Electoral College votes come November. 

Some key swing states could be slipping from the president’s grasp, if new polling is to be believed. According to the poll reported by Puck, Mr. Biden is losing North Carolina and Georgia by more than ten points, Arizona by nearly ten points, Nevada by nine points, and Pennsylvania and Michigan by seven points.