Public opinion is bimodal in the US, shaped by the two party system. During the broadcast era media were forced to tailor their message for the median because y

Public opinion is bimodal in the US, shaped by the two party system. During the broadcast era media were forced to tailor their message for the median because you can only broadcast one message. However the median is actually smaller than the two modes on either side. When multicast messaging became technologically possible, it made economic sense to tailor your message for one of the modes, both to differentiate and to tap into a more engaged audience, the extremes of which had been ignored during the broadcast era.