Specifically radio, but also TV and daily newspapers.
Name one even slightly left radio station in Iowa. And NO NPR is not left. Maybe 30 years ago when Newt came on the scene but NPR has been intimidated into a nice little voice of non-committal on nearly everything.
There are very few over-the-air liberal station in the whole country, let alone Iowa. Yet Iowa's AM dial from stem to stern is blanketed with extreme right wing radio from WHO in Des Moines to WMT in CR to WOC in Davenport and (IIRC) KXEL in Waterloo and stations I can't remember in Council Bluffs and Sioux City.
That is the big stations. Seems like every town of a thousand especially in Western Iowa has a thousand watt station. And the farmers listen all day every day. And those stations are played in gas stations and retail stores and restaurants day in and day out.
So long before we knock on any door or call any phone in a rural area the groundwork for conversations has been laid and it is conservative talking points. These talking points are reinforced by small weekly conservative papers and the Sinclair and Fox stations that re the 'local' TV stations.
In this game we come in in the fourth quarter trailing 28 to 0 and try to play catch up. It is really really hard when you are that far behind.