The US Senate passed a $1.2 trillion Infrastructure Investment and Jobs Act on Tuesday. The bill, which authorizes $550 billion in new infrastructure spending over the next five years, represents the largest federal investment in the country's infrastructure facilities in decades.

Now it awaits a vote in the House of Representatives.

Although the scale of the bill is much smaller than the $2.3 trillion US President Joe Biden proposed, it should be noted that 19 Republicans have joined the Democrats in favor of the legislation. No wonder, Biden praised the bill for promoting bipartisan cooperation.

The last round of large-scale infrastructure construction in the United States came in the 1950s. Propelled by then US president Dwight Eisenhower, the US started building its Interstate Highway System in 1956, which became the most advanced highway system in the world and ushered the US into its long period of post-war prosperity.

However, Biden's proposed Build Back Better plan still faces obstacles as the political polarization and internal frictions in the US remain grave, and the resurgence of the COVID-19 pandemic has ended his honeymoon period.

Speaker of the House of Representatives Nancy Pelosi, as a representative of the progressive Democrats, has claimed if the Senate does not pass a $3.5 trillion reconciliation bill, which will help improve the social security and welfare system of the US, the House will not vote for the Infrastructure Investment and Jobs Act.

In other words, the progressive Democrats are pushing for the two spending bills to be a bundle, while the moderate Democrats think that will be too aggressive and will incur more uncertainties and risks. So the intra-party rivalry within the Democratic Party itself might render the Senate's passing of the act meaningless.

Even if the House of Representatives gives a green light to the act, it will take a long time to implement the planned infrastructure construction and many uncertainties may arise in the process that may paralyze it at any time.

Not to mention the difficulties in fundraising, and the concern of serious inflation if the administration tries to resolve it through printing bank notes.