In the early to mid-1960s, left-wing activists compelled Democratic officeholders to take a stand against racism and poverty and mobilized behind the new policies they enacted. That secret socialist Martin Luther King Jr. and such SNCC workers as John Lewis and Fannie Lou Hamer thrust the demand for Black liberation to the front of the liberal agenda. The Civil Rights and Voting Rights acts were the fruits of their struggle. In The Other America , Michael Harrington, an outspoken socialist, eloquently revealed the extent of poverty in the nation, motivating aides to John Kennedy and Lyndon Johnson to create programs like food stamps and Medicaid that at least helped reduce it.

Later that decade, radicals who were female or homosexual or disabled made headlines by asserting their precious, unfulfilled right to be respected as such both in law and the wider culture. In 1972, three years after the Stonewall riot helped birth a new liberation movement, the Democratic National Convention held serious debates about gay freedom as well as abolishing restrictions on abortion. The backing of feminists and the LGBT community would soon enable the party to present itself as a tolerant force that appealed to young, mostly secular voters in particular.

The rise of conservative movements and politicians from the 1970s on and the fragmentation between insurgent activists and liberal Democrats prevented any new alliance from forming. But a revival occurred early this century when protests against the Iraq War and the suffering of the Great Recession combined to create a fresh set of progressive movements—and to elect Barack Obama president.

In one sense, the left that thrived during the Obama years and kept growing after Trump’s election in 2016 differed from its progenitors. Unlike labor’s “new millions” in the 1930s, the Black freedom movement of the 1960s, or the anti-war movement later that decade, the newest American left rallied around no single issue that united its parts and stimulated its growth. Proponents of Occupy, Black Lives Matter, the Green New Deal, and a new union militancy applauded one another’s demands while organizing separately. Notwithstanding their diverse passions, nearly all activists agreed that decades of conservative thinking and policies, under presidents and congresses of both parties, had turned the United States into a meaner nation in which the rich invariably got their way. Equality—in all its meanings—was their common desire.

Leading Democrats warmed to these movements rhetorically, while they hedged on passing the kind of sweeping programs that activists demanded. During the fall of 2011, Nancy Pelosi, the former and future speaker of the House, said of Occupy Wall Street, “I support the message to the establishment, whether it’s Wall Street or the political establishment and the rest.”

Two months later, Barack Obama called economic inequality “the defining issue of our time…. Because what’s at stake is whether this will be a country where working people can earn enough to raise a family, build a modest savings, own a home, secure their retirement.” But the president made no serious attempt to get Congress to enact the Employee Free Choice Act, labor’s main legislative priority. At Pelosi’s insistence, he did make it a priority to pass the Affordable Care Act—a down payment of sorts on the universal coverage leftists had long advocated.

To have an African American as president also gave the new Black Lives Matter movement both a sense of hope and a target on which to train its frustrations with the slow pace of change. Some lashed out at Obama and other members of the Black elite, in and out of government, for preaching to young African Americans in poor communities a gospel of “respectable” speech and dress instead of enacting policies that would give them a good education and secure jobs at living wages.

At the same time, the enthusiasm for Obama’s presidency, which never flagged among most African Americans, did help gain the Black left a nationwide audience for the first time in decades. Organizers of mass protests could point to the gap between Obama’s rhetoric about racism and his lack of progress in combating the suffering it caused. As the journalist Jelani Cobb observed, “Until there was a Black Presidency it was impossible to conceive of the limitations of one.”

During Obama’s time in office, the most successful movement on the broad left was one with no explicit connection to class or racial equality. The LGBTQ activists who pressed for legalizing same-sex marriage managed to turn an extension of the sexual freedom espoused by cultural rebels in the 1960s into a demand for equal protection under the law. Four years after running for the presidency as an opponent of gay marriage, Obama changed his mind or, more likely, decided to help increase the speed at which the winds of politics were already blowing. In June 2015, by a single vote, the Supreme Court, in Obergefell v. Hodges, agreed, and marriage equality became the law of the land.

Although Obama’s gradual “evolution” on same-sex marriage frustrated its supporters, his change of position accelerated the pace of their victory. The president’s new stance immediately became that of his party. It helped win over Black churchgoers as well as bind most young people of all races to the Democrats—when they could be bothered to vote.

Clear evidence that a mostly young left was thriving inside as well as outside the party emerged during the final year of Obama’s tenure—in the extraordinary presidential run by an independent senator in his 70s who had often criticized the incumbent for not following through on his progressive promises. When Bernie Sanders announced his candidacy in 2015, he had already spent more than half a century advocating for an agenda that would turn the United States into a social-democratic nation—Finland with a lot more people and much warmer summers. By deciding to run as a Democrat, he infused the party with more progressive energy than at any time since the heyday of the Black freedom movement and the Great Society.

One result of Sanders’s campaign was that the party’s platform in 2016 leaned further leftward than any since the days when party leaders were proud to wear the liberal label. “More than anyone else,” commented the veteran progressive journalist Harold Meyerson, “Bernie created the current American left, but just as much, by running for president, he revealed its existence—surprising the nation, surprising the left, surprising himself.”

Joe Biden is hardly the best figure to bridge the current divide between establishment Democrats and a left that veers between disgruntlement and rage. I wish he had decided, after the midterms that went surprisingly well for his party, to bow out of the race and leave younger, more inspiring politicians to compete to take his place.

But aside from his policy toward the war in Gaza, he has accomplished more that leftists should cheer—and with exceedingly narrow majorities in both houses of Congress—than any Democrat since LBJ (who enjoyed a much larger majority in Congress). Under Biden, planned investments in clean energy go far beyond any previous legislation; the government has the power to negotiate the prices of ten popular drugs with Big Pharma and has capped the cost of insulin; and the administration is doing what it can to protect the right to abortion. No president before Biden gave such open support to strikes and labor organizing. And only the damn filibuster prevented the Senate from enacting the PRO Act, which would give workers who want a union strong legal weapons to prevent employers from denying them that freedom.

Although Democrats have been steadily losing the support of working-class voters, particularly white ones, their commitment to using the government to curb corporate power as well as empower employees has actually grown. A new scholarly article by Jacob Hacker and three other political scientists convincingly argues that both in its language and policies, “the party’s use of enhanced government spending and regulation to achieve society-wide economic goals continues to get pride of place.” Every workday, the pro-union majority on the National Labor Relations Board and Lina Khan, the most aggressive chair of the Federal Trade Commission in memory, provide evidence of that.

Of course, progressives should continue to protest Biden’s failure to restrain Israel’s deadly assault on the people of Gaza. But there is no reason they cannot, at the same time, make plans to do what they can to elect him and other Democrats in the fall. If in 1936, leftists could rally to the reelection campaign of Franklin D. Roosevelt, who also enjoyed enthusiastic support from the solid white South, their ideological successors ought to be able to campaign for a liberal president whose military aid to a longtime American ally they abhor.

Time and again, Americans in a hurry to reach the promised land have thrown up fresh ideas, challenged entrenched elites, engaged in grassroots agitation, and pushed liberals down paths they may otherwise have shunned or tiptoed along at a craven pace. While the passion of their creed sometimes blinded leftists to the exigencies of the moment, they cannot be separated from the history of American reform.

But a relentless drumbeat of cynicism and hostility directed at the Democratic Party will surely set back the momentum for progressive change. In 1976, amid another presidential campaign, the veteran organizer Bayard Rustin wrote:

Genuine radicalism…is not measured by how loud and abusively one can shout or by the purity and beauty of one’s rhetoric. Rather, genuine radicalism seeks fundamental change through concerted, intelligent and long-range commitment.… Wherever we look we can find fault. But the only result of endless fault-finding is that you end up in a corner with the few people who are as good and pure as you are…. Those self-appointed spokesmen who raise divisive issues to prove the superiority of their politics are not really radical. By confusing and distracting from the real sources of social change, they retard the struggle for equality and justice.