Reveling in warm reviews for a fiery State of the Union speech, Joe Biden was set to hit the campaign trail on Friday, heading for Philadelphia as his re-election rematch with Donald Trump finally began in earnest.

Three days after the former president dominated the Super Tuesday primaries and saw off the former South Carolina governor Nikki Haley, his last rival for the Republican nomination, Biden was set to speak at a middle school in Wallingford, the sort of suburb that has trended Democratic as Republicans have marched to the right.

Pennsylvania is also a battleground state, won by Biden in 2020 but targeted by Republicans not only as they seek to take back the White House but as a step towards regaining the Senate majority.

Public opinion that Biden is too old for a second term persists but the 81-year-old president was on his way to Philadelphia with a spring in his step.

Heralding a pugilistic speech in which Biden attacked Trump without uttering his name, championed Democratic policies and parried Republican catcalls, the president’s campaign said he had “laid out his unifying vision for the nation”.

That vision, the campaign said, meant “building an economy that gives everyone a fair shot, protecting reproductive freedom, standing with our allies, and defending democracy.

“It’s a vision that could not be more different than Donald Trump’s plans to enact revenge and retribution, strip Americans of their fundamental rights, and spread hate and division.”

The campaign also said voters watching the speech “overwhelmingly approved of the ‘fiery’, ‘strong’ and ‘powerful’ vision from President Biden”.

Republicans naturally disagreed.

The far-right Virginia congressman Bob Good attempted to keep a spotlight on Biden’s age, calling his delivery on Thursday night less presidential and more “like an angry old man with a poor memory shouting at people to get off his lawn”.

But such complaints were undermined by two factors. First, the 42-year-old senator chosen to reply to Biden, Katie Britt of Alabama, delivered a bizarre and poorly received speech of her own. Second, at 77, Trump is just three and a half years younger than Biden and frequently muddles words and mixes up names.

In his own response, Trump – who left office with the economy cratered by Covid, Congress reeling from an insurrection linked to nine deaths and more than 1,200 arrests, and who faces 91 criminal charges and multimillion-dollar civil penalties – accused Biden of being “on the run from his record”.

Biden, Trump said, was “lying like crazy to try and escape accountability for the horrific devastation he and his party have created, all the while they continue the very policies that are causing this horror show to go [on]. We cannot take it any longer as a country”.

On Friday, though, that “horror show” administration welcomed 275,000 jobs added in February and unemployment at 3.9%.

“Job gains remain solid,” said Nela Richardson, chief economist at ADP, a payrolls firm. “Pay gains are trending lower but are still above inflation. The labor market is dynamic.”

Even Stephen Moore, an economist Trump tried to appoint to the Federal Reserve board and who is now part of Project 2025, a plan for a rightwing takeover of the federal government, celebrated economic conditions.

“One thing Biden said last night was true,” Moore told Fox Business. “It is true that the United States today has the strongest economy. There is no question about it.”

Contacted for comment, Moore said: “No I don’t credit Biden for the economy. It IS true that we have the strongest economy but as I said, we are the least rotten apple in the cart. Most of the rest of the world is in recession.”

Asked who he credited for the strong economy, if not the man who has presided over it for three years, Moore did not immediately reply.

As Biden headed for Pennsylvania, his campaign parried criticisms that did arise from his State of the Union address.

Asked about Biden’s use of the word “illegal” to describe an undocumented migrant, which angered progressives, Michael Tyler, the communications director, turned the question back on Trump.

“I know it may have been difficult to hear over the incessant heckling of Marjorie Taylor Greene,” Tyler told reporters, referring to the extremist Georgia Republican who prompted Biden’s remark, “but we should be very clear about what the president was saying when it comes to fixing our broken [immigration] system and to rejecting the cruelty in the hateful extremism being pushed by” Trump and Republicans.

Biden was working to pass bipartisan reform, Tyler said, while Trump used migrants as a “political punching bag” and “peddl[ed] Nazi rhetoric”.

Asked if Biden’s remark might hurt outreach efforts with Latino voters, Tyler said the campaign would “demonstrate the clear contrast” with Trump.

“We are running against a man who was promising to rip kids away from their mothers again, who’s promising to erect mass deportation camps, who is promising to end birthright citizenship and is using hate as one of its chief political currencies,” Tyler said.

Julie Chavez Rodriguez, Biden’s campaign manager and the granddaughter of the great labor leader Cesar Chavez, said: “Our community knows Joe. They know who is fighting for our community.”

Sources outside the campaign praised Biden too. Justin Wolfers, a professor of public policy and economics at the University of Michigan, saluted “a muscular speech”. Larry Sabato, director of the Center for Politics at the University of Virginia, hailed “a home run”.

Rick Wilson, a Republican operative turned co-founder of the anti-Trump Lincoln Project, said Biden’s performance “should settle this crapulous conventional wisdom media trope of ‘he’s too old’ once and for damn all”.

Democrats, Wilson said, now have “a perfect way to shut this garbage talking point down: ‘You saw that State of the Union speech. Joe Biden is sharper than Donald Trump and ready for the fight.’”