An intriguing analysis by RIccardo Puglisi and James Snyder, published this month in NBER (gated), finds statistical evidence for a correlation between newspapers’ endorsement patterns (R vs. D) and the papers’ news coverage of scandals involving Republican and Democratic politicians:

[T]hose with a higher propensity to endorse Democratic candidates in elec tions give significantly more coverage to scandals involving Republican politicians than scandals involving Democratic politicians, while Republican-leaning newspapers behave in the opposite way. This bias in the coverage of scandals is not connected to the editorial page, but also affects the news section. While the fraction of stories devoted to political scandals is on average very small, the magnitude of the coverage bias effect is very large in relative terms: the differential coverage of Republican versus Democratic scandals by a newspaper with a propensity to endorse Democratic candidates which is one standard deviation higher would be larger by around 26 percent.