A groundbreaking study of news coverage of the center-right Tea Party finds that MSNBC has gone out of its way to malign the intelligence and ideology of the movement and its members while Fox News has acted as a “guard dog” to protect it from liberal attacks.

In the first-of-its-kind study published in the authoritative International Journal of Press/Politics, two scholars reviewed stories about the Tea Party on MSNBC, Fox, CNN and from the Associated Press and found that only CNN and the AP provided largely unbiased coverage focused more on the movement’s politics and policies than personalities.