WASHINGTON — President Biden is set to use his State of the Union address Thursday to promote his vision for a second term to a dispirited electorate who questions whether he’s up to the job and to warn that the GOP front-runner, President Trump, would be a dangerous alternative.

Mr. Biden’s third such address from the House rostrum will be something of an on-the-job interview, as the nation’s oldest president tries to quell voter concerns about his age and job performance while sharpening the contrast with his all-but-certain 2024 rival.

The president hopes to showcase his accomplishments on infrastructure and manufacturing, as well as push for action on aid to Ukraine, tougher migration rules, restoring access to abortion, and lowering drug prices, among other issues. Mr. Biden was also going to unveil an expanded plan to raise corporate taxes and use the proceeds to trim budget deficits and cut taxes for the middle class.

As he does so, though, the 81-year-old president will be closely watched not just for his message but for whether he can deliver it with vigor and command.

The president will also try to make this State of the Union, with all its accompanying pomp, a more intimate moment. The White House press secretary, Karine Jean-Pierre, said Mr. Biden sees the speech as a “continuation of conversations” he has had with Americans as he travels the country.

“It’s built on those conversations, that experience that he has,” she said Wednesday.

Mr. Biden spent last weekend working on the speech in the seclusion of the Camp David presidential retreat with his closest aides and presidential historian Jon Meacham. He was expected to keep fine-tuning it right into speech day, Ms. Jean-Pierre said.

The president will be speaking before a divided Congress that has few recent legislative achievements. In the GOP-led House, Speaker Johnson took power five months ago after the chaotic ouster of Speaker McCarthy. 

Legislators are still struggling to approve funding bills for the current year and have been deadlocked for months on foreign assistance bills to help Ukraine stave off Russia’s invasion and support Israel’s fight against Hamas.

The State of the Union address is a marquee night on the White House calendar, offering presidents a direct line to a captive audience of lawmakers and dignitaries in the House chamber and tens of millions of viewers at home. Even so, the night has lost some of its luster as viewership has declined.

“You always hear people say, ‘Oh, the speech has completely lost its relevance. Just send a PDF of it. It should be a video.’ That’s just such nonsense,” said a speechwriter in the Clinton White House, Michael Waldman. “… It may not be as big as Taylor Swift at the Super Bowl, but it’s a big audience for a political speech.”

Biden aides inside the White House and on his campaign are hoping for some fresh viral moments — like when he tussled last year with heckling Republicans and chided them for past efforts to cut Medicare and Social Security.

Mr. Johnson, eager to avoid a similar episode this year, in a private meeting on Wednesday urged Republicans to show “decorum” during the speech, according to a person familiar with his remarks to lawmakers.

Mr. Biden goes into the speech with work to do shoring up his standing. Just 38 percent of  American adults approve of how he is handling his job as president, while 61 percent disapprove, according to a recent survey by the Associated Press-NORC Center for Public Affairs Research.

The same survey found that more than 6 in 10, 63 percent, say they’re not very or not at all confident in Mr. Biden’s mental capability to serve effectively as president. A similar but slightly smaller share, 57 percent, say that Mr. Trump lacks the memory and acuity for the job.

The already intense scrutiny of Mr. Biden’s age was magnified when special counsel Robert Hur raised questions about the president’s mental acuity in his report last month on Mr. Biden’s handling of classified information.

President Obama’s 2012 campaign manager, Jim Messina, said Thursday’s speech offers Mr. Biden an important opportunity to address voter concerns.

“The more people see him doing his job, the better,” Mr. Messina said. “And the more people see him out there being the president of the United States, the better off we are.”

With Hur set to testify on Tuesday before lawmakers about his investigation, Messina said, Mr. Biden’s address could serve as a “prebuttal” to the special counsel’s appearance.

Mr. Biden is expected to paint an optimistic future for the country as the massive pieces of legislation he signed into law during his first two years in office are implemented. He also was set to warn that the progress he sees at home and abroad is fragile — and particularly vulnerable if Mr. Trump returns to the White House.

Republicans, in contrast, are describing the current state of the union with dark, menacing terms — like “crisis” and “catastrophe” — that echo the dismal tones Mr. Trump sounds on the campaign trail.

“America is in decline, nothing he says tomorrow night is going to change that,” Mr. Johnson said Wednesday.

This year, Mr. Biden could also face protests and heightened emotions — particularly among his base supporters — over his staunch backing for Israel’s war against Hamas in Gaza. The White House had initially hoped a short-term ceasefire would be in place by the speech. It blames Hamas for not yet accepting a deal brokered by America and its allies.

The president will also issue an emphatic call for lawmakers to pass sorely needed defense assistance for Ukraine. Acute ammunition shortages have allowed Russia to retake the offensive in the 2-year-old war.

The GOP-controlled House has refused to act on a Senate-passed version of the aid legislation, insisting on new stiffer measures to limit migration at the border, after Mr. Trump used his influence to help sink a bipartisan compromise that would have done just that.

Senator Murphy, a Connecticut Democrat, said he was expecting that Mr. Biden “knocks Republicans in the teeth” for rejecting the border security deal.

“Voters want a candidate who cares about the border, but they want a candidate who’s going to do something about it, not just complain about it,” he said.

Access to abortion and fertility treatments also is expected to be a key component of Mr. Biden’s speech, especially in light of a controversial ruling from Alabama’s Supreme Court that has upended access to in vitro fertilization treatment in the state.

One of first lady Jill Biden’s guests for the speech will be a Texas woman, Kate Cox, who sued the state, and ultimately traveled to another state, to obtain an emergency abortion after a severe fetal anomaly was detected.

The White House also invited union leaders, a gun control advocate, and others that Jill Biden and her husband have met as they traveled the country promoting his agenda. 

The Prime Minister of Sweden, Ulf Kristersson, will also attend to mark his country’s accession to NATO in the wake of Russia’s war in Ukraine.

Going into the State of the Union, Mr. Biden also has raised the problems of “shrinkflation” — companies putting fewer pretzels in the jar and less yogurt in sealed cups — and so-called “junk fees” on services.

Neither is a prime driver of inflation, but the White House hopes to show consumers that Mr. Biden is fighting for them.