The Service Employees International Union, which represents 2 million workers in health care, property services and the public sector, announced Thursday that it will throw its grassroots organizing power behind presumptive Democratic nominee Joe Biden in the 2020 presidential campaign.

How does this change the race? By winning SEIU’s endorsement, Biden can tap into a network of tens of thousands of volunteers and political organizers to boost his ground game. The union has announced plans to invest $150 million in a voter engagement campaign targeting infrequent voters of color in several battleground states and has urged Congress to expand voting access during the coronavirus pandemic. SEIU says its members have already reached out to more than 3 million voters in Florida, California, Michigan, Wisconsin and Pennsylvania through a text message campaign to help them register and sign up to vote by mail. That gives Biden a small leg up on President Donald Trump, whose campaign launched a multimillion-dollar legal effort to block expanded ballot access and has railed against mail-in voting.

How does this influence Biden’s policies? SEIU represents sectors of the workforce that have been acutely affected by the pandemic, including many essential workers like airport and frontline health care employees. The union also backs the Fight for $15 campaign, which has organized fast food worker strikes across the country over safety conditions and fair wages. SEIU President Mary Kay Henry serves on the Biden-Sanders unity task force on health care, helping shape the Democratic platform. The coalition released its policy recommendations on Wednesday, which called for raising wages for health care workers to $15 an hour and increasing diversity in the field. SEIU has also released a 2020 agenda that calls on candidates to expand workers’ access to unions, establish universal health care, reform the immigration system and address climate change.