What media bias? Conservative and liberal labeling in major US newspapers

This article tests the hypothesis that major U.S. newspapers disproportionately label conservative politicians. We quantitatively analyze ideological labels of U.S. congress-persons and senators in newspaper articles. We then qualitatively review these articles, seeking to discern if any patterns exist, and if so, why. Disproportionate labeling of conservatives exists but not in a way that constitutes "bias," as newspapers often label liberals, at times more than they do conservatives. These labeling patterns may be explained by the rise of conservatives who entered Congress in 1994, the political pejorativization of the word liberal, and the increased conservative ideological tenor of the Congress during the past fifteen years. We conclude by discussing possible implications of our findings.