The news may not tell you what to think, but it tells you what to think about
During the 1968 US election, Maxwell McCombs and Donald Shaw asked undecided voters in Chapel Hill, North Carolina which issues mattered most, then measured how much coverage local media gave each issue. The two rankings matched almost exactly. Their 1972 study launched agenda-setting theory: by choosing what to cover, the media shape which problems the public sees as important.