Public investment is back, and it is popular. More than two out of three Americans support President Biden’s $2 trillion proposal to invest in infrastructure, according to a poll conducted by Monmouth University.

The wide support for Biden’s plan — including a commitment to rebuild U.S. roads, bridges and tunnels, as well as to invest in broadband Internet, electric vehicles and the fight against climate change — signals an inflection point in American politics. Observers on the left and right have likened Biden’s ambitious agenda to that of President Franklin D. Roosevelt, whose New Deal transformed the nation in the 1930s, building public works projects and providing relief and employment to those hit hard by the Great Depression.

The many successes of the New Deal do offer potentially instructive examples for our present moment, but only if we move beyond the romanticized image of Roosevelt’s program that often persists. The truth is that the core of the New Deal managed to achieve sweeping popularity but also generated fierce opposition, exposing how steep Biden’s challenge is.

Roosevelt inherited an unprecedented crisis in 1933 with nearly a third of the American workforce out of a job. That spurred him to undertake an equally unprecedented expansion of federal authority. But most of the programs often considered the New Deal’s legacy today — such things as Social Security, federal bank deposit insurance and the Securities and Exchange Commission — don’t really capture the essence of Roosevelt’s sweeping agenda.

In fact, the central enterprise of the New Deal was its public works programs. Through Interior Secretary Harold Ickes’s Public Works Administration (PWA) and Harry Hopkins’s Works Progress Administration (WPA), the federal government spent huge sums of money in almost every county across the nation. The WPA’s 1935 appropriation of $4.88 billion was by itself the equivalent of 135 percent of federal revenue, or about 6.7 percent of the nation’s gross domestic product, in that year (for reference, the GDP today stands at $22.05 trillion). These public works agencies put millions of people to work, constructing roads, sewers, libraries, hospitals, hydroelectric dams and hundreds of airports.

But the New Deal didn’t just construct basic physical infrastructure. Roosevelt and his aides believed in socially useful infrastructure that invested in the future. This vision meant that building new schools in almost half of the nation's counties joined the list of New Deal projects.

These programs leveraged the abilities of an uncommonly gifted group of public servants. Hopkins, Ickes and their subordinates were skilled public administrators, with a talent for tapping the legal and engineering expertise they needed. The New Deal’s public works programs brought a raft of lawyers, civil engineers and economists into the federal workforce to review project plans, evaluate their soundness and make informed decisions about allocating funds. Furthermore, these New Dealers were comfortable working with the business community to achieve their goals: For example, rather than building things itself, the PWA accepted bids from private construction companies, which then did the building for its projects.

Nor did government-sponsored economic development simply represent the expansion of federal power at the expense of state and local authority. Instead, it was a true partnership — the New Deal approved and funded projects that were proposed by state and local governments themselves. State and local governments provided matching funds to receive federal grants and loans, so their tax dollars supported Roosevelt’s programs, as well.

But for all it accomplished, the New Deal had shortcomings: Given the vast nature of the Great Depression, public works programs were not able to eliminate mass unemployment — only the mobilization of the U.S. economy during World War II accomplished that goal. And racism meant that all Americans did not benefit equally from the programs. Nonetheless, one accomplishment is clear: The New Deal successfully used federal authority to transform the infrastructure of a sprawling country.

Fittingly then, in 1939, when George Gallup’s Institute of Public Opinion asked Americans to name “the greatest accomplishment of the Roosevelt administration,” their No. 1 answer was “Relief and the WPA.” And, in retrospect, it is easy to see why this was the case: Jobs and improved infrastructure made for a popular combination during an economic crisis. Yet, when asked by Gallup in the very same poll to identify “the worst thing the Roosevelt administration has done,” the No. 1 answer was the same New Deal program: the WPA. How could the same public works and employment program be simultaneously so popular and unpopular?

The answer was rooted in the boldness of the New Deal. Roosevelt’s team worked strenuously to strike a balance between public administration and private capitalism, all while eliciting the tangible support of state and local governments. At the same time, they were not afraid to deploy federal resources and spend public funds on a massive scale.

This scale — and the very success and popularity of the WPA — generated a political backlash. Using the power of government to provide assistance to the least fortunate members of society was controversial. While many middle- and upper-class Americans welcomed improved infrastructure and the economic recovery generated by Roosevelt’s administration, a smaller but still substantial number resented the idea of public funds going to the WPA workforce.

The New Deal’s opponents mocked WPA workers as lazy public employees who leaned on shovels at the construction site while they waited to collect government paychecks they did not deserve. “We Piddle Around,” conservatives charged, mocking the WPA’s acronym. Wealthy business executives, led by the du Pont family, created the American Liberty League to attack Roosevelt. The league sponsored radio addresses and distributed pamphlets charging that the New Deal was a waste of taxpayer money and warning that federal intervention in the economy posed a threat to democracy itself.

This fearmongering stoked angst among those Americans who saw such government intervention as radical. While Roosevelt remained popular, reelected for an unprecedented third and fourth terms in 1940 and 1944, voters also elected more conservatives to Congress in the midterm elections, with Republicans gaining seats in 1938 and 1942, and taking full control of the House and the Senate in 1946.

The existence of this very real backlash, even though it initially came from a minority, is important to remember as Biden takes on an equally bold building program. Roosevelt achieved unprecedented popularity and had a top-rate team implementing his agenda. Yet, even their competence could not prevent a slice of the electorate from deriding the WPA.

That forgotten reality exposes the importance of competence in implementing Biden’s vision. Given the size and scope of his program, critics will be looking to pounce on the smallest mistake, or any story that might be sensationalized to cast the entire enterprise as wasteful, foolish or a gross overreach by the federal government. And Roosevelt’s experience reveals how small the margin for error is. Roosevelt commanded a far greater majority than Biden, and even his most popular program generated backlash. Biden can ill afford a less smooth rollout, or flubs that enable his critics to caricature the entire program.