This week's Mainstream Media Scream features MSNBC "Hardball" host Chris Matthews ranting about Senate Republican leader Mitch McConnell.

On his April 24 show, he noted McConnell's low unfavorable rating while rapping the Kentucky senator's vote against stricter background checks for gun buyers.

"Somehow, I have a different attitude towards the Republicans and Democrats who voted on this thing. I don't know why it is -- because I'm not always partisan -- but I really do have a problem with Mitch McConnell. I would like to see him get stung hard on this one. So, why do I think like that? Because he tends to be an SOB, generally. Does anybody like that guy?"

Media Research Center Vice President of Research Brent Baker explains our pick: "Matthews should have given his 'I'm not always partisan' line to Conan O'Brien for a joke about himself at Saturday night's White House Correspondents' Association Dinner. Even Matthews' colleagues would have laughed at such a claim."

Rating: Four out of five screams.