I get the feeling that conservatives who are informed get most of their news on the radio on the way in and way out of work.
In my locality (near Milwaukee, WI), outside of the socialist run helhole of milwaukee proper, is a ring of counties that are some of the most, if not most reliably conservative in the country.
The AM stations have a few very conservative talk shows in the morning and afternoon and a few moderately conservative shows- nearly everyone in the conservative areas listen to them daily. The further out you go from the range of these stations, the less conservative and less informed people are in general.
The left has tried their hand at opposing radio programming, but have all been failures.