That didn't take long at all. A few days after Don Imus' racially-charged remarks about the Rutgers women's basketball team, CNN set its sights on Rush Limbaugh and other conservative talk radio hosts. On Tuesday's "Paula Zahn Now," host Paula Zahn teased an upcoming segment by noting, "If you think some of the things Don Imus says are insulting, you haven't heard anything yet." She then played Rush Limbaugh's criticism of embryonic stem cell advocate Michael J. Fox from last fall.

Later, in the segment itself, Zahn juxtaposed Don Imus's words with controversial remarks by Limbaugh, Neal Boortz, Michael Savage, and Randi Rhodes -- three conservative/libertarian hosts to one ultra left-wing host. Then on his Wednesday evening program, CNN host Larry King gave former Air America radio host and Senate candidate Al Franken (D-Minn.) a platform to attack conservative talkers.

When King asked if CBS should let Imus stay on the air, Franken said it was up to CBS, and then went on the offensive against "right-wing radio," focusing on Glenn Beck, King's colleague on sister network CNN Headline News. Franken called for Beck's ouster while King failed to question Franken's assertions that "I've heard Rush Limbaugh say things that are worse than this." King only corrected Franken when he said that Beck worked on CNN, not its Headline News spinoff.

An excerpt of Zahn's segment on controversial talk show hosts, which focused on Limbaugh.

ZAHN (voice-over): They are controversial for a reason. Their on-air rants provoke outrage from some listeners and dogged loyalty from others. It all adds up to millions of dollars a year in advertising revenue and millions of dollars for the hosts.

And while radio host Don Imus calling the Rutgers University women's basketball team "nappy-headed hos" is certainly beyond the bounds, it is not the first time offensive comments have been spewed on the radio. Conservative Rush Limbaugh, who has offended just about every minority group, drew special criticism for attacking actor Michael J. Fox.

LIMBAUGH: In this commercial he is exaggerating the effects of the disease.

ZAHN: When Fox appeared in a campaign ad for Democratic candidates supporting stem cell research, he was trembling from his Parkinson's disease. Limbaugh accused him of faking his symptoms.

LIMBAUGH: He is moving all around and shaking, and it's purely an act. This is the only time I have ever seen Michael J. Fox portray any of the symptoms of the disease he has.

ZAHN: Limbaugh later apologized. But the criticism for that low blow hasn't stopped him from lashing out at presidential hopeful, Barack Obama, calling him "Halfrican."

LIMBAUGH: Barack Obama has picked up another endorsement, Halfrican-American actress Halle Berry. As a Halfrican-American, I am honored to have Ms. Berry's support, as well as the support of other Halfrican-Americans.

Calling Barack Obama "Halfrican" is lashing out? Let's compare that to what Al Franken said on Larry King's program on Wednesday.

FRANKEN: I have heard a lot of talk radio -- now, I will give you an example. CNN has Glenn Beck on. Glenn Beck asked my congressman, Keith Ellison, who is the first Muslim to be elected to Congress, you know, I just want to ask you, how do I know that you're not working with the enemy?

And he said that -- I think he said it on CNN. But he certainly is -- he's on CNN. I don't know why that wasn't grounds for CNN thinking, well, maybe Glenn Beck shouldn't be on. I mean, how dare he say that to a congressman who has just been elected?

And I hear this kind of thing a lot of time. I monitored a lot of right-wing radio when I was doing my show and before it. And I've heard Rush Limbaugh say things that are worse than this.

Actually, Beck had said to Congressman Ellison, "I have been nervous about this interview with you, because what I feel like saying is, ‘Sir, prove to me that you are not working with our enemies.'And I know you're not. I'm not accusing you of being an enemy, but that's the way I feel, and I think a lot of Americans will feel that way."

One of the targets of Paula Zahn's segment, Neal Boortz, wrote on Thursday that "There is not one single significant right-of-center radio talk show out there that is not going to come under fire." It appears now that CNN launched the opening salvo, and it won't be long before other mainstream media outlets start firing their ammo.

—Matthew Balan is a news analyst at the Media Research Center.