"The echo chamber doesn't need any bad connectivity to function. Limbaugh's followers have full access to outside sources of information. According to Jamieson and Cappella's data, Limbaugh's followers regularly read - but do not accept - mainstream and liberal news sources. They are isolated, not by selective exposure, but by changes in who they accept as authorities, experts and trusted sources. They hear, but dismiss, outside voices. Their worldview can survive exposure to those outside voices because their belief system has prepared them for such intellectual onslaught."