For a week now, I haven’t been able to stop thinking about what just happened in Kentucky, where progressive firebrand Charles Booker almost beat all the odds in the US Senate Democratic primary race. It’s not because I’m any stranger to electoral heartbreak. When I was 20, I moved from Brooklyn to a town I’d never heard of in Wisconsin to help a Democrat named Rob Zerban run a campaign to unseat Representative Paul Ryan, then the chair of the House Budget Committee. Years later, I moved to New Hampshire to work for the first Democratic socialist in modern history to mount a serious campaign for president. I’ve had my share of heartbreak.

It’s because I’ve seen this happen too many times before. When a race is decided by a margin that’s more than 10 percent, it’s easy to blame the media, or fundraising imbalances, or feel like it was fundamentally inhospitable terrain. But given how close the race came last week, it felt like a win really was within reach, and any little decision, any little investment could have made the difference.

I hope the progressive movement takes that seriously. A pro–Green New Deal, pro–Medicare for All, pro-UBI Black candidate came incredibly close—in Kentucky!—to beating someone who ran as a Democrat, but who has said she would have voted to confirm Brett Kavanaugh’s nomination to the Supreme Court. I met Booker a year ago, when he was first thinking about running, and joined his campaign in April, when he was down 50 points in the polls. The final margin ended up at 2.8 percent, which was unthinkable when he started, with pennies in the bank, firmly in the single digits against the Democratic Senatorial Campaign Committee’s anointed candidate Amy McGrath, who appeared invincible sitting on top of a $40 million war chest.

At the beginning of his campaign, Booker had only what he likes to call “faith the size of a mustard seed.” That and the backing of the Sunrise Movement, who met with him and did the slow, grinding work of supporting his candidacy before anyone else had heard of him. If you looked at the numbers back in February, it was easy to think Booker’s candidacy was an unwinnable distraction. It also just felt unwinnable—a Black man running statewide in Kentucky on the Green New Deal? Get real. So most advocacy groups and progressive organizations stayed on the sidelines.

But Sunrise saw it another way: They saw it as their job to take on the slow, difficult fight, not only because we need more progressive senators in order to pass progressive legislation, but also because committing resources early on would ultimately grow and strengthen the movement even in the event of a loss. So they helped produce his launch video, worked with the team to build the bones of his campaign, devoted e-mail and fundraising resources to it, helped recruit a team, and set up a voter contact operation for the only Black candidate in the race back when everyone else in DC was waiting with bated breath to see if radio host Matt Jones would decide to challenge McGrath. They saw in Booker’s candidacy an opportunity to reframe the debate around the Green New Deal, which right-wing fearmongers had long dismissed as the elitist fever dreams of white liberals, instead of as a truly broad-based populist governing vision. What would it mean, they wondered, for a Black candidate to run and win on a Green New Deal in the heart of America’s coal country?

A whole lot, as last week’s results would prove. Sunrise’s early investment, and Booker’s immense heart and talent as a candidate, closed the gap from a 50 percent deficit to less than three points. Representative Alexandria Ocasio-Cortez, Senator Bernie Sanders, and Senator Elizabeth Warren all backed Booker, and national progressive groups like MoveOn, Indivisible, and the Progressive Change Campaign Committee began to follow suit. It became the national story to watch and a focal point of the battle between the party’s establishment and insurgent progressive wings.

But as the results rolled in last week, I kept wondering: Why did the help take so long? How could it be that Amy McGrath, backed by Senator Chuck Schumer, the DSCC, and their donors, blanketed the Kentucky airwaves with $3 million in the final week alone to paper over her weaknesses as a candidate, while major progressive groups on our side sat out the race or endorsed in the final hours before election day?

All told, Booker’s campaign spent $1.1 million on TV advertising, while McGrath unloaded a cool $12 million onto the airwaves over the course of the primary. Despite that, we came within 2.8 percent. Clearly, we didn’t need spending parity to win, but what would an extra $300,000 in help from outside groups have meant one month before Election Day, while Kentuckians were sending in their ballots by mail, and could it have put us over the top? That’s a question I’ll be asking myself every day for the next several months.

It’s hard to keep watching our ascendant movement blow the most winnable electoral contests of our time: Jessica Cisneros could be in Congress, Tiffany Caban should be the Queens County district attorney, Cristina Tzintzun Ramirez deserves the chance to take on John Cornyn, and it’s heartbreaking that Abdul El-Sayed isn’t the governor of Michigan. Falling just short again, watching history continue to repeat itself, compels discussion.

The truth is: All of these races look unwinnable until they’re not. But isn’t that what movement organizations are here to do—take on the worthy fights, and turn the improbable into the possible? What we’ve proven on Tuesday is that these races are winnable if we try, even when we’re badly outspent. But that can’t happen if the cavalry arrives five days before Election Day, which is when the biggest pro-Booker independent expenditure came in. That’s too late to make a real difference—and the establishment knows it. That’s why the biggest pro-McGrath independent expenditure came in 48 days before the election. We need established progressive organizations to learn from that, and do what Sunrise did with Booker, and what Justice Democrats has impressively done with Jamaal Bowman.

If progressive organizations and advocacy groups keep waiting for candidates to catch fire and have a moment before they hop on board, we’re doomed to keep losing winnable races by a few hundred votes. Put another way, if you wait until you feel thirsty to drink water, it’s too late; you’re already dehydrated. We need more organizations to understand what groups like Sunrise and Justice Democrats already do: that winning requires showing up early, and doing the hard, tireless work of slogging in the dark—not showing up to cut a check four days before the election and add their logo to a press release. I hope our movement learns that in time for 2022. Because somewhere out there this week, the next Alexandria Ocasio-Cortez, or the next Charles Booker, is starting to think about picking up the baton.