This week's Mainstream Media Scream features Washington Post editorial writer Colbert King comparing Mitt Romney to impeached former President Andrew Johnson in his weekly column.

"Johnson stood by as Southern states enacted 'black codes,' which restricted rights of freed blacks and prevented blacks from voting," King wrote, adding, "Romney stood by last year as Republican-controlled state legislatures passed voter-identification laws, making it harder for people of color, senior citizens and people with disabilities to exercise their fundamental right to vote."

Media Research Center Vice President of Research Brent Baker explains our pick: "King couldn't be more vituperative. Fearing a Romney victory, he resorts to discrediting it as a win for racists. To compare mainstream conservative policies with armed government officials enforcing segregation and a systemic denial of basic civil rights in the years after slavery is a new low. King has outdone Chris Matthews."

Rating: Five out of five screams.