At 9:45 p.m. Tuesday night, Larry Krasner was declared the winner of the Democratic Primary for District Attorney of Philadelphia.

At his victory speech, the community organizers and activists who formed the backbone of his campaign cheered as Krasner said “this is not about a person… this is now and will always be about every person.”

Krasner, a civil rights attorney whose candidacy was laughed at as a joke-candidacy by the political establishment only a few months ago, won decisively with a higher than usual voter turnout. His win is a major victory for social movements fighting for racial and economic justice.

So what can progressives learn from Krasner’s win? Below are five reasons behind the victory; five lessons for organizing and winning in today’s political climate.

1. Right Message, Right Messenger

Larry Krasner won because his platform spoke to the broadest coalition of voters in the city. He believed everything he said, he didn’t triangulate, and it showed and resonated.

For decades, overpriced Democratic campaign consultants have urged candidates to avoid saying anything too controversial or taking positions “too far to the left.” The result has been stale candidates who fail to inspire or put real choices on the ballot. Other early entrants in the DA primary like Joe Khan, Rich Negrin and Michael Untermeyer adopted this approach wholeheartedly, including taking on “reform” messaging when they sensed the political winds of the #resistance. But nothing about their campaigns or past actions made them credible as change agents. They promised to serve as competent managers of business as usual, and at best make incremental adjustments.

By contrast, Krasner openly and honestly decried the broken, racist criminal justice system from the outset and ran on a platform of complete overhaul. Only Krasner was unabashed in his support for the Black Lives Matter Movement - without which his campaign would have been impossible.

When a candidate articulates a truth that everyone knows, but that career politicians are too afraid to say, they create a powerful emotional connection with voters. Few can do this authentically; when Krasner spoke about decarceration, ending the drug war, and holding cops accountable, voters knew that he was genuine. His decades of work as a civil rights attorney demonstrated that he believed what he said.

2. Ground Game!

Nobody had a ground game as good as Team Krasner’s. While most of the campaigns paid for election day workers to hand out fliers at the polls, only Krasner inspired massive numbers of volunteers to knock doors as early as mid-March. By election day, supporters of Larry Krasner had spent weeks talking to tens of thousands of voters all across the city.

Reclaim Philadelphia and 215 People’s Alliance led a coalition of local organizations that included Neighborhood Networks, Pennsylvania Student Power, and the BLOC Party. Collectively, that coalition knocked nearly 60,000 doors in the 10 weeks before the election. Rather than having rushed conversations with complete strangers, these volunteers had long discussions with their neighbors about the criminal justice system, mass incarceration, and the meaning of public safety.

This field program only represents a fraction of the doors knocked by supporters of Krasner. The Working Families Party ran an independent expenditure that knocked 70,000 doors. The Krasner campaign itself and unions like AFSCME 1199c also knocked tens of thousands of doors and pushed hard to turn supporters out to vote.

Coalitions like this one require long-term investment in relationship building. Grassroots armies of volunteers don’t materialize overnight; they take time and care to organize and train. Organizations that use base-building organizing models can move votes and volunteers on a large scale. Future progressive candidates should note that it is worth investing in talented organizers who can train volunteers to take the campaign message door-to-door.

3. Community Credibility

Although Larry Krasner had never run for office prior to his insurgent campaign for DA, he was well-known to the political community. He had spent decades representing community organizations, labor unions and elected officials. As a result he was widely known as a talented and principled attorney.

This, above all else, is why Krasner was able to assemble such a large coalition. Activists and organizers who knew and believed in Krasner started knocking doors early; as more people became aware and excited about Krasner’s candidacy it opened pathways for robust coalition-building.

Eventually, progressive unions, a number of high profile local politicians, and many African American ward leaders enthusiastically supported Krasner. But these actors, no matter how ideologically aligned, could never have taken that risk without strong and sustained demonstration of grassroots support.

4. Television

Larry Krasner’s campaign was the beneficiary of a substantial independent expenditure by the Philadelphia Justice and Public Safety PAC. Funded by billionaire George Soros, this PAC spent over one million dollars on television advertisements that celebrated Krasner’s work representing activists for Black Lives Matter and Occupy Wall Street.

While many will be eager to credit these television buys for Krasner’s victory, the truth is more complicated. Television isn’t everything: opponent Michael Untermeyer matched the Justice and Public Safety PAC in spending on advertisement and was able to reach substantially more viewers. Untermeyer ultimately finished in 5th place with only one supporter for every five Krasner voters.

The greater impact of the Soros money was that it demonstrated Krasner’s viability as a winning candidate. To win, Krasner needed the support of ward leaders and elected officials who liked Krasner but hadn’t considered him a competitive candidate. The massive spending by Soros’ PAC signaled that Krasner’s campaign was not just a “protest” candidacy, but that he was actually in it to win it.

5. Donald Trump

Over 152,302 voted in Tuesday’s primary. This represents a significant increase from the last competitive DA primary in 2009, when 104,589 voted. The most visible bumps were in Northwest Philadelphia, Center City and the gentrifying neighborhoods just outside of Center City. In other words, turnout grew the most in communities with high numbers of middle-class professionals — the same areas where people have flocked to the “Trump Resistance.”

Krasner won the election on Tuesday not only because he captured votes in this expanded electorate, but also because he captured the largest share of the vote in working class Black neighborhoods. The foundations for Krasner’s victory were laid by the Black communities of Philadelphia - those most impacted by the crisis of mass incarceration. This cause was then adopted by white progressives who voted in higher numbers in this DA primary than in any other DA primary in this century.

In the era of Trump and the failure of the ruling class, there are many who hunger for real change. Krasner’s victory demonstrates that there are new opportunities for candidates who come out of social movements to present new visions, break free from false choices, and win.

Cross-posted from Medium