Earlier this year, we won a commanding, 15-point victory in a special election to the New York State Senate to represent a suburban swing district north of New York City. The race received significant attention because it was pivotal for Democrats to gain power after years of Republican control.

With so much on the line, wealthy conservative donors and special interests spent millions in attack ads to stop me from being elected. We beat them because we built a unique coalition geared to increasing turnout through intensive face-to-face contact, not because of an inexorable Blue Wave. While my experience was in a state senate race, it is one Democratic candidates for Congress should learn from to know how to win this fall.

Political analysts see Democrats’ best path to retaking the House of Representatives running through suburban districts that include communities much like the one I was elected to represent. To win in these districts, Democrats must focus on three essential strategies: mobilizing a broad coalition of grassroots supporters; taking a progressive, values-based message directly to voters; and consistently reminding voters of the personal stakes of the election.

Our campaign was powered by an army of more than 3,000 volunteers who knocked on tens of thousands of doors, made phone calls, attended rallies, and helped get the word out. We were able to knock on 60,000 doors over the last five days of the campaign.

What made this manpower possible was our campaign’s efforts to build a broad coalition of unions, Democratic activists, Indivisible groups, women’s groups and community groups. We called it a “Big Tent” because everyone did not have to agree on every issue. Pipefitters and electricians worked alongside Planned Parenthood supporters; Teamsters and hospital workers canvassed together with members of Indivisible; teachers and bus drivers worked with community activists.

Many of our volunteers never knew someone in a union. And many union members were unfamiliar with the upper-middle-class, highly educated women that flocked to my campaign. The marriage of these groups and volunteers doesn’t just happen — it requires a specific degree of dedication to relationship and coalition building that often gets lip service but is rarely central to the campaign strategy because most consultants still favor media and mail, not mobilization at the grassroots.

A face-to-face program played a crucial role in getting our message to voters, because, as any candidate who has run for office in the era of President Trump can tell you, breaking through all the noise is an immense challenge That is why we complemented our canvassing with big investments in digital advertising, much more than state senate campaigns typically have.

We also ran a positive message in our campaign literature, advertising and — most important — direct voter contact. Voters got to know me and who I fight for, not just who or what I am against. A recent column in the New York Times wisely pointed out that populist progressive messages about “lifting everyone up” resonate with voters, and that’s certainly what I saw on the campaign trail. Sharing my vision for a political system that works for all of us and reflects our values, not just those of the powerful and well-connected, resonated while solely anti-Trump messages did not.

Voters know we are in the midst of extraordinary times, but it’s up to candidates to convince their constituents that voting is how they can produce change. Would we be a state that protects the air we breathe and water we drink in the face of the Trump administration’s slash-and-burn approach to regulating polluters, or would we be a state beholden to fossil fuel and chemical companies? Would we lose more of our friends and neighbors to opioid addiction, or would we make clear to pharmaceutical companies that their complicity in this crisis will not be tolerated? Would we be a state that ensures fair school funding so that every young person can graduate from high school college- or career-ready, or would we be a state that allows underperformers to fall further and further behind?

Voters in my district answered these questions, and did so decisively. If Democrats in the suburbs consider this grassroots-focused approach, engage a broad coalition of labor, women and progressive activists with a positive message, their constituents may answer similarly.