This week's Mainstream Media Scream goes to MSNBC's Hardball host Chris Matthews who, in a special Saturday edition after Mitt Romney picked Paul Ryan as his running mate, railed against the choice. He twice claimed that Ryan's budget hurts the needy, charging that the House Budget Committee chairman's spending plan "really screws the people who desperately need Medicare and programs like that." And: "He's screwing the people he doesn't expect to vote for him. The people he doesn't expect to vote for him, he's screwing."

Media Research Center Vice President of Research Brent Baker explains our pick: "Another gutter shot for Matthews. Instead of seriously addressing Ryan's policy prescriptions to avert a fiscal catastrophe, Matthews impugns Ryan's motives with cheap demagoguery - and yet still has the gall decry the low tone of the campaign he's fueling."

Rating: Four out of five screams.