When rapper Killer Mike calls the Bernie Sanders campaign to pitch ideas or make suggestions, they pay attention, he says.

“I think more rappers need to endorse [Bernie Sanders],” Killer Mike told The Daily Beast. “I’ll suggest some rappers who are incredibly brilliant…and I’ll get those [phone] numbers and pass those onto [Sanders’s] press secretary. When it comes time to organize hardcore events on the ground that will mobilize the young black vote, I’ll reach out to the appropriate contact in the campaign.”

Killer Mike, who belongs to the hip-hop group Run the Jewels, has emerged as Sanders’s most prominent, and perhaps most passionately committed, celebrity endorser (one of many “ Artists for Bernie ”) as the senator fights his uphill battle against Hillary Clinton for the Democratic presidential nomination.

“What I have never gotten is a no-response, or dismissal, from the campaign,” he said. “His campaign really is one where I’ve seen people share ideas, and have people follow up.”

Killer Mike (birthname: Michael Render) has long staked out his claim in the music industry and the hip-hop world. Rolling Stone has dubbed him both “ a thunderous rapper ,” and “Southern rap's top political theorist,” for instance. But during this election, the 40-year-old rapper further raised his profile in political and media circles with his full-throated endorsement and volunteer work for the 74-year-old Jewish socialist.

And he wants more of his colleagues to join the revolution.

“Every rapper who I see as a comrade, or a peer, whose number I have, I will absolutely say, ‘Hey, man, you know, give this person [in Bernie’s team] a call, and let them think about these ideas,’” Killer Mike said. “I look forward to doing more [for the campaign], but we got an album to record.”

The new Run the Jewels album is due out in the fall, he says.

“I expect to see other [rappers] come out and support him — on the bigger plateau of rappers — because the stuff that we rap about, the stuff that we talk about, the stuff that outrages us, Sanders’s policy deals with that,” he emphasized. “So I think as more rappers connect with that, you’re going to see his favorability grow among young African-Americans, because so many of them are inclined to listen to the music, and to listen to the people who make the music.”

The idea of a famous musical artist hitting the campaign trail for a presidential candidate is nothing new. But what makes Killer Mike’s association with the Sanders 2016 campaign unique is how he has gone above and beyond what is expected of your typical celebrity surrogate. (See: Lena Dunham and Katy Perry for Hillary Clinton, or Phil Robertson for Ted Cruz, who basically just show up at events, and sing or say nice things about their candidates.)

Killer Mike helps organize and plot events and outreach efforts; he revs up the crowds and introduces Sanders at rallies; he has hosted phone-banking for Bernie in his hometown of Atlanta, Georgia. Nowadays, he practically tweets nonstop about why more Americans should Feel The Bern. To that end, Killer Mike advised the campaign to book more appearances on radio shows geared towards black audiences.

“I told them, ‘Hey, black people need to hear from you — do black radio,’” he said. “And he did black radio. And he’s doing more black radio.”

Together, Killer Mike and Sanders have formed what has to be one of the odder — or at least more unexpected — pairings of the 2016 campaign. The Atlanta rapper has been a diehard fan at least since June, when he first tweeted his endorsement. “It’s official,” Mike wrote on Twitter over the summer. “His call [for] the restoration of the voters rights act sealed the deal for me.”

And Sanders is only Killer Mike’s latest beacon of political hope. He has been participating in campaigns ever since he was 8, when he was pounding the pavement with his family. Killer Mike says he knew the late civil rights activist and pastor James Orange, who he considers a mentor.

“He taught me how to organize,” he said. “This is what I do, this is what I’ve always done: volunteer. Ever since I was a kid, if a politician jumps out, I give it a try, hit the streets — harass people into voting.”

Mike has tried to “harass” citizens into voting for candidates such as Jesse Jackson, Barack Obama, Walter Mondale, Bill Clinton, and former Atlanta Mayor Shirley Franklin. In the past eight months, all of the organizing chops that he has honed over the decades have been devoted exclusively to Sanders.

Both Killer Mike and Sanders’s team are well aware of the major difficulties the senator has had in capturing enough of the black vote. Last month, his campaign held a press call to discuss the menu of specific initiatives related to their African-American outreach. This game plan included embarking on tours of barbershops and beauty salons where Sanders could reach black working-class communities.

The idea for Bernie’s barbershop tour actually stemmed from a brief moment of casual conversation between the lawmaker and the rapper, the latter of whom operates a barbershop in Atlanta.

“The barbershop tour was my idea that I brought to him,” Mike said. “In terms of the organizing, what I claim responsibility for...is the barbershop tour. That is the industry I'm in. It’s an industry where you can engage working class men, and puts them directly in Sanders’s face…It's safe to talk in a barbershop. You're not going to be judged by religious dogma, or anything else.”

So far, the political bromance between Mike and Sanders has demonstrated a loyalty that works both ways. As other celebrities such as Will Ferrell get cold feet and defect from Sanders to Clinton, Killer Mike is staying put. (He is still not sure if he will support Clinton in the general election, should she lock up the party’s nomination.)

And when Mike took some heat for repeating a quote that having a “uterus doesn't qualify you to be president” (referring, of course, to the former secretary of state), the Sanders campaign went to bat for him, and dismissed the controversy as petty "gotcha politics."

"If you wanna ask me about uteruses, I’m not going to talk about that,” Killer Mike told The Daily Beast, simply stating that he was “sick of that stuff,” and that the degree to which his comment was amplified over the past week was a symptom of “part of what's wrong with this country.”

And as the rival campaigns head into Super Tuesday, Killer Mike is digging in to do whatever he can to help the cause. But he’s not delusional: he see the same delegate math everyone else does, and knows that Sanders’s path to the nomination is steep. Regardless, he is keeping the faith.

“I’m just gonna maintain hope, I really am,” he said, saying that Sanders has been performing much better than observers previously anticipated. “I’m like the guy at the horse race with a ticket in his hand.

“As long as he’s in the race, the policies that matter about people are going to be talked about,” he continued. “And that’s what I talk in my music. That’s what I talk about on my Twitter feed. That’s what I talk about in real life.”