US President Joe Biden speaks at the dedication of the Dodd Centre for Human Rights at the University of Connecticut on October 15, 2021. Photo: AFP

US President Joe Biden is expected to hit the road Wednesday to show off the huge new infrastructure bill passed last week, hoping to reap its benefits politically even as he watches his approval ratings slump.

The Democratic president chose Baltimore, a port city less than an hour's drive from Washington DC, to explain to the nation why and how the country will spend $1.2 trillion on its sagging infrastructure. 

On Monday evening, in an interview on local television in Cincinnati, Ohio, the Democratic leader insisted it would only be a "matter of weeks" before the effects of the massive investment plan would start to be seen. 

Days earlier he had predicted it would be "two to three months" before the public starts to see the real effects of the bill on expanding internet networks, roads, bridges, drinking water pipes, electric car charging stations and a slew of other projects. 

The president is counting on the program producing an impact - at least politically - before Americans vote in midterm elections in a year's time.

That election, traditionally a challenge for the party in power, could well cost the Democrats their slim majority in Congress. 

In the meantime, Biden's cabinet has been rallying to play up the legislative win, while the president is trying to mobilize local party officials to provide after-sales service for the gigantic spending bill.

It is popular in principle, but its precise details remain unclear to the wider public, especially after weeks of complicated negotiations in Congress. 

And another battle is already underway in Congress over the other part of Biden's economic and social reform agenda: an up to $1.85 trillion plan that includes major investments in health, education, tackling climate change and expanding social welfare programs.

After Baltimore, the president will continue to plug his message on the ground, deputy White House spokeswoman Karine Jean-Pierre said Tuesday. 

Biden likely has the experience of Barack Obama - under whom he served as vice president - in mind. 

Obama steered through a huge stimulus package totaling almost $800 billion in 2009, with vastly differing economic and political results.

While the measure rebooted the recession-hit economy, Republicans racked up a strong surge in the following midterm elections. 

Obama later surmised that his mistake had been to forget that, beyond the process of making decisions, the president must also "tell a story to the American people that gives them a sense of unity and purpose and optimism, especially during tough times."

That is what Biden, whose White House is full of former senior officials from the Obama administration, appears to be trying to do now. 

AFP