"Dear Trump, I wrote you but you still ain't callin."

President Trump has sparred with opponents with his clever nicknames, brutal Twitter takedowns and comic imitations. But when it comes to Marshall Bruce Mathers III, also known as the rapper Eminem, Trump is doing something even more devastating – he's completely ignoring him.

In a recent interview with Vulture, Eminem expressed frustration that the commander-in-chief seems to be indifferent to the rapper's insults.

"I want him to answer me because I got ideas for all kinds of s--t to say back to him if he does," Eminem told the magazine. "I'm not going to give any away now, but I've got lines ready if he says something about me. I get almost flustered thinking about him – that's how angry he makes me."

Eminem has had Trump in his sights for some time, notably blasting the president in a 4.5 minute freestyle rap at the BET Hip Hop Awards in October. But Trump, who almost never misses a chance to hit back at critics, seems utterly unaware of Eminem's existence.

"He makes my blood boil," the 45-year-old complained of the president. "I can't even watch the news anymore because it makes me too stressed out."

Eminem also said he hopes Trump is impeached.

Understand what makes a liberal tick. "The Liberal Mind: The Psychological Causes of Political Madness," by Dr. Lyle Rossiter explains it all.

The rapper tried to pose as a concerned citizen in his interview.

"All jokes aside, all punch lines aside, I'm trying to get a message out there about him," he claimed. "I want our country to be great too, I want it to be the best it can be, but it's not going to be that with him in charge."

Eminem specifically identified Trump's speech decrying some Mexican illegal aliens as "rapists" as a turning point for him.

"From that point on, I knew it was going to be bad with him," he said. "What's he doing putting people against each other is scary f---ing s--t. His election was such a disappointment to me about the state of our country."

As a white rapper who was once an icon to white working-class youth in states such as Michigan, there is some overlap between Eminem's fan base and Trump's core constituency. Eminem said he never dismissed Trump's chances, partially because he saw how the then-candidate appealed to the white working class.

"I did have a feeling early that he could win," he said."Pretty much everyone I knew was like, 'No, he can't get elected,' and I was watching those rallies going, 'Yo, man, this s--t is real.' But I don't know if that has anything to do with any parallels between me and him. I took the fact I was poor white trash and I owned it. So I could understand why people who grew up in similar situations would relate to what I was saying. But I don't know, man, the differences between me and him are bigger than any parallels. He's made the racists come out. He's made it acceptable for the white man to feel oppressed."

Eminem also implicitly criticized Taylor Swift, whom the media has been endlessly pressuring to condemn Trump.

"I don't know anything about Taylor Swift's situation," he said. "I can only speak for me, not her. I do feel like when you have a platform, it's important to use your voice. You can loudly call bulls--t on things that not everyone can. I don't know if anyone has a responsibility to do that. That's something they'd have to look inside themselves and figure out. That's what I did, and I decided I needed to speak out."

Eminem’s sudden attack of conscience over impolitic language may seem laughable.

The rapper became prominent two decades ago with lyrics celebrating what Lynne Cheney termed "violent misogyny." In songs such as "Kill You," the artist graphically describes the satisfaction of raping and murdering his mother, followed by gleeful anticipation of murdering any other woman he might happen to encounter. His song "Kim" depicts the murder of the mother of his child.

Eminem also uses a number of homophobic slurs such as "faggot" in his work, including 2013's "Rap God." Thus, Eminem's discussion in the interview about he uses the application "Grindr" as well as "Tinder" to find dates may raise some eyebrows. "Grindr" is mostly used by homosexual and bisexual men.

Still, despite Eminem's new posturing as a concerned, socially aware American, it isn't the first time he's attacked a Republican president. In his 2003 song "We As Americans," he raps, "I'd rather see the president dead."

As with any other comment that could be considered a threat to the life of then-President George W. Bush, the Secret Service investigated.

Understand what makes a liberal tick. "The Liberal Mind: The Psychological Causes of Political Madness," by Dr. Lyle Rossiter explains it all.