On April 23, the day after Earth Day, a big tent coalition—climate activists, union workers, civil rights leaders, and increasingly desperate young people—will be gathering outside the White House. If you live on the eastern seaboard and are free that Saturday, you should sign up and join them. Here’s why:

Tucked beneath the headlines on Covid and Ukraine, the most important climate legislation in US history – and thus, arguably, in world history – is still stuck in Congressional purgatory. You’d be forgiven if you weren’t fully aware. It is not trending on Twitter. President Biden has mostly stopped talking about it. The enormous moral stakes have been brutally ablated by a broken, farcical, and, above all, extremely boring legislative kludge known as budget reconciliation. The months-long saga has turned Biden’s original “Build Back Better” plan into the juridical equivalent of a Warhol soup can – a ubiquitous token evacuated of any original meaning.

That the public has largely failed to track the world-historical implications of this process is an indictment of the way climate information gets filtered down to ordinary people: in dollar figures no one understands, in line graphs published by obscure wonks on Twitter, in front page headlines that exhaust the emotive potential of journalistic prose. Connecting any of this to, for example, insurance premiums in Miami Beach, or the fate of the world’s remaining sea turtles, or the prospect of your own grandchildren spending the bulk of their crypto-wages on potable drinking water requires an almost mimetic leap of imagination.

And yet, the stakes remain what they are. Passage of the bill’s half-trillion dollars-worth of clean energy investments would likely spell the difference between the world’s largest economy meeting its climate goals and blowing right past them. It is not an exaggeration to say that in that balance—between 2 and 3 degrees Celsius of warming, between a government responsive to and avoidant of the greatest crisis of the 21st century – hang millions of human lives. The potential impact rivals that of nuclear war, except in this case the default is catastrophe. The fossil fuel industry has already fired its ICBM at the heart of our coastal cities. It’s up to the Democrats now to turn it around.

And turn it around they still might. Joe Manchin, of his own volition, has returned to the bargaining table with a proposal that could retain most of the original climate investments from Build Back Better and potentially leave room for some investment in low-emission home and health care work. Biden and Schumer must stop at nothing to hold him to his word and land the deal. If they do, they could reverse the narrative of Biden’s presidency overnight. Not only would Biden finally be able to declare victory on his signature policy agenda, he would be offering a direct rejoinder to the crisis in Ukraine, pointing global energy markets toward wind and solar and undercutting fossil-fueled autocrats like Vladimir Putin. For a war-time president, the combination of crisis-response and long-term vision would earn him a place next to Churchill in the history textbooks.

To be clear, I am profoundly angry that it’s all come to this. That not a single one of the Republican cowards who claim concern over climate change – Susan Collins, Lisa Murkowski, Mitt Romney, Lindsey Graham – is even considering voting for the bill. That it’s fate will be determined by a man who makes money hand over fist pumping carbon into the atmosphere. That President Biden had to dispatch the head of the National Economic Council to go zip-lining with Manchin in West Virginia last weekend. That the fate of organized human civilization would at least partially depend on two grown men donning intricate safety harnesses and skimming across a river gorge (though I’ll admit that, compared to your typical round of golf, there was something weird and almost endearing about this particular political mating ritual).

All of which is to say: I won’t let my indignation die. I won’t succumb to the Stockholm Syndrome of the Beltway pundit, who would tell my generation that this is just how Washington works. The point is that Washington doesn’t work. Washington is broken. This process is proof.

But to refuse cynicism is not to refuse strategy. That’s why, on April 23, thousands of people will be showing up in front of the White House – and in key Senate swing states – to make one last play at redemption. That’s why, at the risk of repeating myself, you really should join them. Democrats still have a chance to deliver big on climate. If they fail, we’ll lose far, far more than the midterms.

We cannot allow them to fail.

• Daniel Sherrell is the author of Warmth: Coming of Age at the End of Our World (Penguin Books) and a climate activist