Maryland gubernatorial candidate Ben Jealous, former head of the NAACP, speaks during a campaign stop. (Salwan Georges/The Washington Post)

A coalition of progressive groups and labor unions is spending nearly a half-million dollars to turn out the vote for Ben Jealous in the June 26 Maryland Democratic primary.

The coalition, which includes the Working Families Party, Progressive Maryland and Our Revolution Maryland, announced Friday that it plans to pour nearly $500,000 into targeted mailing, digital advertising and canvassing about 250,000 homes in Baltimore City and in Montgomery, Prince George’s and Baltimore counties.

“This is a competitive election, and the stakes are high,” said Jay Hutchins, acting executive director of the Maryland Working Families. “We need to elect someone who has a willingness and an ability to bring the change we need to Maryland.”

The coalition is targeting black voters — a key voting bloc for Democrats — women and young voters. It plans to tout Jealous’s plans to require a $15 minimum wage, adopt a single-payer health-care system and implement programs to allow students to go to college and universities free.

A Washington Post-University of Maryland poll released three weeks before the primary showed that Jealous, a first-time candidate, is one of two contenders leading a crowded field. Twenty-one percent of likely voters said they support Jealous, while 16 percent support Prince George’s County Executive Rushern L. Baker III. Nearly 4 out of 10 voters were still undecided.

Jealous and his running mate, Susan W. Turnbull, had $660,000 cash on hand as of May 15, according to the most recent campaign filings. They were ahead of Baker and his running mate, Elizabeth Embry, who had $577,000. But they were behind the Baltimore-based ticket of James L. Shea and Brandon M. Scott, who had $1.3 million to spend. Jealous on Friday launched his third television ad, a $140,000 effort that airs in Baltimore markets and focuses on his health-care plan.

The independent campaign behind the get-out-the-vote effort includes a host of groups that have endorsed Jealous over the past year, including the Amalgamated Transit Union, the National Nurses Union and the American Postal Workers Union.

Larry Stafford, executive director of Progressive Maryland, said the members of the coalition are excited about Jealous’s campaign, which also has received the endorsement of U.S. Sens. Bernie Sanders (I-Vt.), Kamala D. Harris (D-Calif.), Cory Booker (D-N.J.) and others.

“I can gauge the energy from our chapters. They have been putting sweat equity into this movement,” Stafford said.

Stafford, who worked on the unsuccessful 2014 gubernatorial campaign of then-Del. Heather Mizeur (D), said: “Progressives are more united in Maryland than I have seen in some time. . . . The difference this cycle is that it’s the populist, progressive crowd along with labor coming together.”

Early voting begins Thursday.