Sen. Bernie Sanders (I-VT) is increasingly using his campaign’s mailing lists and voter data to rally striking workers across the nation.

The Sanders campaign helped organize workers at McDonald’s who walked out last Thursday to demand a $15 an hour minimum wage, marking the second time in the last two weeks the campaign has used its emails lists and voter files to organize picket lines.

“Bernie Sanders is joining in solidarity with McDonald’s workers in Dallas, and you can do the same right here in Iowa,” reportedly read one of the emails the campaign sent out to supporters across the nation last week that also included an RSVP link. “Showing up at a picket line for striking workers is an incredible act of solidarity to show that you support their fight for a better life.”

When workers at the University of California went on strike on May 16 to protest the university system’s reliance on outsourcing and privatizing its workforce, the Sanders campaign blasted out emails to help the organizers.

“Tens of thousands of workers in the University of California system are standing up this Thursday to stop the outsourcing and privatization of union jobs,” the email said while also reportedly including and RSVP link and addresses for picketing locations. “We are hoping you can join these workers tomorrow.”

A local American Federation of State, County and Municipal Employees (AFSCME) spokesman told the Huffington Post that Sanders’s organizing efforts worked, saying that “random supporters” were on the picket lines “because they had received an email or text from the Bernie campaign. That happened all over the place.”

According to the Guardian, the Sanders campaign has also “previously enlisted supporters to turn out for rallies, protests and strikes for workers” at Delta Airlines, Disney, Amazon, General Motors, Wabtec, and Nissan.

Though former Vice President Joe Biden has tried to enlist the support of various labor unions, the Sanders campaign’s strategy to directly help various labor groups organize and strike could make the difference when the party’s critical union voters cast ballots in states like Iowa, Nevada, and California.

“As Bernie says, this is not just a campaign, it’s a movement. We’re building the largest volunteer army in the nation not just to win the Democratic nomination, but also to mobilize people to show up in key fights where people’s lives and livelihoods are on the line,” Bernie 2020 national organizing director Claire Sandberg told the Guardian. “We are proud to uphold Bernie’s commitment to workers and we will continue to activate our supporters and urge them to join picket lines across the country to support the fight for a strong labor movement.”