Maryland’s Republican Senate primary has hit the airwaves, with the two best-known GOP candidates going on the radio before voters head to the polls April 3.

Sen. Benjamin Cardin (D) is strongly favored to win a second term in November, but that hasn’t stopped 10 Republicans from vying for the right to face him.

Former Secret Service agent Daniel Bongino, the most active of the group, will begin airing a radio ad on WCBM in Baltimore Wednesday, with a statewide buy soon to follow.

“Can we all agree that politicians aren’t getting the job done?” Bongino asks in the ad

Calling himself an “outsider,” Bongino says: “Some say this race is an uphill battle, that Maryland is a lost cause. Well, I don’t believe in lost causes, not when it comes to fighting for our children’s future.”

Bongino’s ad buy follows that of former Defense Department official Richard Douglas, who announced a statewide radio campaign last week.

Douglas’s spot portrays Cardin as being asleep on the job — calling him Rip Van Cardin — as gas prices rise.

Like Bongino, Douglas also portrays himself as an outsider. “I’m not a politician,” he says. “I’m an Iraq veteran and small business owner concerned about jobs and our economy.”