The Port of Baltimore dazzled in the setting sun. Giant cranes arched over the Chesapeake Bay, the shoreline stacked with colorful shipping containers. At the center of the tableau was the American president, on a mission to promote his hard-won $1tn infrastructure package.

“Infrastructure week has finally arrived,” Biden said last week, beaming at the mix of elected officials and local union leaders in attendance.

The president’s visit to the bustling port came at the start of a cross-country tour to sell his sprawling public works plan to the American public, in the hope of parlaying the policy achievement into a political victory that will help Democrats keep their slim majorities in Congress.

But while his policies are popular, Biden and his party, presently, are not. Last week, voters turned sharply against Democrats, delivering a number of surprising Republican victories in states Biden won handily in 2020.

The losses jolted Democrats into action on Capitol Hill, even as some moderates wondered if the president had misread his mandate. Within days, they sent the infrastructure bill, gridlocked for months amid intra-party feuding over a separate pillar of Biden’s agenda, to his desk for his signature.

In the weeks ahead, the president’s promotional tour will test his political salesmanship and his theory of governance: that delivering concrete benefits is the best way to rise above the political tribalism roiling the country.

“The American people sent us here to deliver. The American people sent us here to make the government work,” Biden said on Friday, during a cabinet meeting to discuss the implementation of his infrastructure bill. “They sent us here to make a difference in their lives. And I believe we’re doing that.”

Facing daunting odds in next year’s midterm elections, Democrats are pleading with “Amtrak Joe” to make the pitch loud and clear.

Congressman Sean Patrick Maloney of New York, who leads the campaign committee for House Democrats, pleaded with the White House to put Biden on the campaign trail as frequently as possible to trumpet his domestic agenda. In an interview with the New York Times, he said his message to the White House was, “Free Joe Biden.”

“That campaign needs to start now before the next crisis takes over the news cycle,” he said.

On Monday, Biden will sign the measure into law during a ceremony at the White House, surrounded by a bipartisan group of legislators, governors and mayors. Following that, the president will hit the road, with plans to visit a bridge in Woodstock, New Hampshire, and a GM electric vehicle plant in Detroit, according to the White House.

In addition, Biden is dispatching his cabinet members, including the transportation secretary, Pete Buttigieg; energy secretary, Jennifer Granholm; and interior secretary, Deb Haaland, to promote the bill’s investments in states, cities, towns and tribal communities.

So far, the strategy echoes the administration’s “Help is here” tour to showcase the Democrats’ $1.9tn coronavirus relief package Biden signed into law shortly after taking office. But the presidential messaging blitz was soon swamped by the US’s withdrawal from Afghanistan, a summertime resurgence of the pandemic and a rise in inflation.

Even though the legislation sent $1,400 stimulus checks to millions of Americans, expanded the child tax credit program and increased unemployment insurance – all tangible, popular benefits – Democrats hardly reaped the political rewards. An August poll by Daily Kos/Civiqs found that 57% of voters said the Biden administration had not done anything that has benefited them personally.

“Voters don’t go to the ballot box with a spreadsheet of policies. They go with a feeling about who values them,” said Jesse Ferguson, a senior Democratic strategist. The way to show that, he said, was “to deliver on the things that matter to people who work for a living”, like lowering the cost of prescription drug prices, making childcare more affordable and providing paid family and medical leave.

​Whether a concerted appeal from the president ​can overcome ​a toxic political climate​ is an open question for Democrats. Biden’s standing with voters has dropped sharply, particularly among independents. Wide majorities say the nation is on the wrong track. A CNN poll released this week found that six in 10 American believe Biden has the wrong priorities. The number climbed among voters who ranked the economy as a top priority.

As the administration’s messaging campaign ramps up, the White House says its digital team is developing explainer videos and other social content to educate voters about the Democrats’ initiatives. They are also planning for a burst of TV appearances, including with media outlets that serve Black and Latino communities.

The push also includes an emphasis on local news organizations, such as WKRC-TV in Cincinnati, which sat down with Biden on Monday. In the interview, he predicted a long-overdue upgrade for the deteriorating Brent Spence Bridge that stretches between Ohio and the Senate minority leader Mitch McConnell’s home state of Kentucky.

McConnell was one of 32 Republicans in the House and Senate to vote for the legislation that has divided the party. Donald Trump savaged those in his party who supported the measure, blaming them for voting for “Democratic longevity” while his loyalists in the House accused them of disloyalty. Many of them have faced vicious backlash from constituents, including vulgar insults and even death threats.

Speaking in Kentucky, McConnell squashed any suggestion that the unusual display of bipartisanship might extend beyond the realm of roads and bridges.

“Let me sum it up this way,” he said. “I think every step we took this year … except infrastructure is in the wrong direction.”

At home during the congressional recess, Democrats donned hard hats and lined up next to union workers to highlight how the once-in-a-generation investment in the nation’s infrastructure would benefit the wishlist of long-neglected public works projects in their districts and states. The plan, they said, would touch all 50 states, creating high-paying jobs and helping to rejuvenate the economy.

The package, which includes the largest investment in infrastructure since Dwight Eisenhower began the interstate highway system in the 1950s, is popular with voters. But many of the projects won’t be started, much less completed, until long after the midterm elections are decided.

“It is part of our job to let people know exactly what Congress did for them,” Madeleine Dean, a Democratic congresswoman from Pennsylvania, said on a press call showcasing the infrastructure bill’s investments in her state. “We have a lot of educating to do.”

A Monmouth University poll released this week found 65% of Americans support the infrastructure bill while 62% approve of the Democrats’ spending measure. Yet the poll showed that voters increasingly believe Biden’s policies have not helped middle-class or poor families.

Taken together, the results suggest the White House and Democrats “lack a cohesive and concrete message about how this bill will help the American public”, said Patrick Murray, director of the Monmouth University Poll.

The measure’s bipartisan passage has given some Democrats fresh optimism that they can muster the votes to pass a second, even larger domestic policy measure and begin to reverse their political fortunes ahead of next year’s midterm elections.

“Democrats are delivering – and we are making sure that the American people know it,” Jaime Harrison, chair of the Democratic National Committee, said in a statement. The DNC is “doubling down” on their outreach to voters, working with state and local parties to help translate how the plan will benefit their communities.

Matt Barreto, a Democratic pollster and senior adviser to Building Back Together, a group advocating for Biden’s agenda, said voters were swayed by results.

“I really like our chances if we are messaging on very popular policy that we have passed and signed into law and the other side is complaining about cultural issues,” he said.

A Navigator Research survey found that Biden’s overall approval rating climbed in the days since Congress passed his bipartisan infrastructure deal. The same survey showed that support for the major pieces of Biden’s agenda remains high as a growing number of voters say they’ve heard about the bill.

Yet the challenges threatening to derail Biden’s PR campaign are myriad. When Democrats return to Washington next week, a new fight awaits over the next phase of his agenda. Republicans are eager to weaponize rising inflation, using it to attack the spending plan as reckless. And even when Biden attempts to take a victory lap, as he did in Baltimore on Wednesday, the news of the day interferes.

Designed as a solution to fix the nation’s crumbling infrastructure, Biden said the measure would also address immediate economic concerns caused by rising inflation and supply chain bottlenecks.

The obstacles were underscored by his appearance in Baltimore. In his speech touting the “once-in-a-generation investment” in the nation’s infrastructure, he also delivered a lengthy explanation of supply chains and conceded that “consumer prices remain too high”.

After his remarks concluded, Biden, a retail politician at heart, waded into the crowd, joking and laughing as he worked the rope line and glad-handed local officials.