Put differently, those issues and views that are subject to high-level political debate are most likely to receive news attention that is wide-ranging issues not subject to debate receive less critical attention.
“Indexing” is a theory of news content and press-state relations first formulated as the “indexing hypothesis.” At its core, the indexing hypothesis predicts that news content on political and public policy issues will generally follow the parameters of elite debate: when political elites (such as the White House and congressional leaders) are in general agreement on an issue, news coverage of that issue will tend to reflect that consensus when political elites disagree, news coverage will fall more or less within the contours of their disagreement.