During her speech at Washington Square Park in New York last week, which drew a massive crowd of both supporters and curious bystanders, Massachusetts Sen. Elizabeth Warren evoked the legacy of Frances Perkins, the longest-serving secretary of labor and first female member of the presidential Cabinet.

The Warren campaign’s decision to stage a speech at the famous park in lower Manhattan was inspired partly by the fact that it is a block away from the infamous Triangle Shirtwaist Factory, where 146 garment workers—most of them young immigrant women—died in a fire in 1911. The disaster, as Warren told her audience, prompted major reforms, which Perkins was instrumental in pushing. As the presidential candidate put it in her speech, “With Frances working the system from the inside, the women workers organizing and applying pressure from the outside, they rewrote New York state’s labor laws from top to bottom to protect workers.”

Twenty years later, Franklin D. Roosevelt selected Perkins as his labor secretary (a position she would hold during his entire presidency), and the administration passed everything from Social Security and unemployment insurance to minimum wage and the Wagner Act, which guaranteed labor’s right to organize. One “very persistent woman,” Warren declared, “backed up by millions of people across [the] country,” achieved major structural reforms that had a transformative effect on the country.

Warren isn’t the first 2020 Democratic candidate to give a major speech on the legacy of the New Deal. In June, in his widely discussed speech on democratic socialism, Sen. Bernie Sanders repeatedly invoked FDR and his “bold and visionary leadership” as an example for what we need today.

Though some commentators (including me) questioned the Vermont senator’s decision to make FDR and New Deal liberalism the focal point of a speech about democratic socialism, which presumably goes beyond Roosevelt’s brand of social democracy (a program designed to preserve and stabilize American capitalism, not replace it), from a strategic standpoint, it makes perfect sense to employ Roosevelt as a model for the kind of leadership needed in the 21st century.

Roosevelt, along with members of his administration like Perkins, fought for transformative change that was, in Sanders’ words, “opposed by big business, Wall Street, the political establishment, by the Republican Party and by the conservative wing of FDR’s own Democratic Party.” At the time, Roosevelt was called everything from a fascist to a communist, and he had to deal with smears from members of his own party, such as 1928 Democratic presidential candidate Al Smith, who founded a group called the Liberty League to oppose the New Deal. At a 1936 Liberty League rally, Smith gave a then-27-year-old Joseph McCarthy a template for his future tactics, painting Roosevelt as a Bolshevik in disguise: “There can be only one capital, Washington or Moscow. There can be only … the clear, pure fresh air of free America, or the foul breath of communistic Russia. There can be only one flag, the Stars and Stripes, or the flag of the godless union of the Soviets.”

Roosevelt and his administration didn’t just face ad hominem political attacks, but institutional barriers that threatened to make real structural reform impossible. With a conservative majority, the Supreme Court ruled numerous New Deal policies unconstitutional, and stood in the way of any kind of economic reform. At one point, historian Jeff Shesol tell us in his 2010 book, “Supreme Power: Franklin Roosevelt vs. The Supreme Court,” FDR thought that the court would “nullify virtually everything of significance that the administration had done.” This thought didn’t lead Roosevelt to despair, however, as he believed that after the “nine old men” overruled his popular reforms, it wouldn’t be long before “the nation’s streets were filled with marching farmers, marching miners, and marching factory workers.” In other words, Roosevelt was prepared for a fight, and counted on popular support against the so-called “economic royalists.” There would always be those who cried “unconstitutional” at “every effort to better the condition of our people,” Roosevelt observed in 1937. “Such cries have always been with us; and, ultimately, they have always been overruled.”

Roosevelt’s struggle with the Supreme Court culminated with his plan to add more justices to the court, which ultimately failed, but not before the court—Justice Owen Roberts in particular—shifted its tune on New Deal legislation.

Both Warren and Sanders have invoked Roosevelt and the New Deal not just because of policies, but because of the aggressive style of politics that Roosevelt and his team employed to achieve such transformative change. Roosevelt wasn’t afraid of being denounced as a communist or a dictator by right-wing detractors, and he eagerly embraced conflict with the wealthy business leaders who funded such groups as the Liberty League. Roosevelt used the bully pulpit to push his progressive agenda and famously welcomed the hatred of his opponents, who stood against economic and political reform widely supported by the American people—just as many progressive reforms are today.

One of the most frequent criticisms leveled at progressive candidates, often from centrists who claim to sympathize with their agenda, is that their plans are unrealistic and will never make it past Congress, let alone the Supreme Court. Reporting on Warren’s speech at Washington Square Park, The Atlantic’s Russell Berman observed that while Warren’s policy plans are “detailed and specific, her strategy for achieving them is less so.” Like Sanders, Warren calls for a sustained grassroots movement to pressure Washington, but, according to Berman, “that was also Obama’s plea, and while the former president was able to enact the Affordable Care Act, Wall Street reforms, and a large economic-stimulus package early in his tenure, his entreaties for outside help did not succeed in pressuring Republicans to support his plans.”

This is the conventional wisdom one often hears today about the Obama years, and while it is certainly true that President Obama faced unprecedented Republican obstructionism, it is simply false to claim that the 44th president fought aggressively for a progressive agenda and did everything he could to push for radical change. Even before he entered office, Obama had settled on a “pragmatic” response to the financial crisis, hiring centrists and neoliberal ideologues like Timothy Geithner, Larry Summers and Rahm Emanuel, while desperately working to achieve a “post-partisan” consensus (which was far more naive than the progressive approach toward movement-building).

One notable example of the Obama administration’s timid response was its failure to push for legislation that would have allowed judges to modify the terms of home mortgages, colloquially known as “cram down.” As David Dayen reported in 2015, it was within Obama’s power to prevent millions of people from losing their homes (just as it was within the administration’s power to criminally prosecute bank executives for their fraudulent behavior). “The administration’s eventual program, HAMP, grew out of the banking industry’s preferred alternative to [cram down], one where the industry, rather than bankruptcy judges, would control loan restructuring,” Dayen writes. “Unfortunately, the program has been a success for bankers and a failure for most hard-pressed homeowners.”

The idea that Obama was once a populist, and that a Warren or Sanders administration would end up just like the Obama administration did, is simply wrong. The two leading progressive candidates have already expressed a willingness to adopt the Rooseveltian style of politics that Obama was never willing to adopt, and the 44th president never favored the structural changes that the former do. “I am prepared to go to every state in this union and rally the American people around [a progressive] agenda to put pressure on their representatives, whether they are Democratic or Republican,” Sanders recently remarked in an interview, saying that he would also support primary challenges to Democrats who are not supportive of progressive policies like “Medicare for All.” This is an aggressive strategy in the tradition of Roosevelt, and it is the only strategy that could potentially lead to his progressive agenda becoming a reality in the future.

It is completely legitimate to ask how progressives would pass major legislation without a supermajority in Congress, and the fact is that Roosevelt had much more favorable circumstances in 1933 than any Democratic president is likely to have in the foreseeable future. There are certain measures that could give Democratic presidents some wiggle room. Warren has advocated eliminating the filibuster, for example, while Sanders has, curiously, rejected this approach, favoring the complicated budget reconciliation process instead.

None of this will matter, however, if progressive Democrats don’t manage to create a wave of popular enthusiasm for their agenda. It is important for progressive leaders to be honest and forthright about this to their supporters. None of their proposals stands a chance without a popular movement that goes well beyond the election cycle. Roosevelt understood the power of popular will; perhaps it is time for Democrats to refresh their memory.