Some groups have a greater ease of access than others and are thus more likely to get their demands placed on agenda than others. For instance, policymakers have been found to be more influential than the overall group of news sources because they often better understand journalists' needs for reliable and predictable information and their definition of newsworthiness. Cobb and Elder ascribed even more importance to decision makers, claiming that in order for an issue to attain agenda status, it must be supported by at least some of key decision makers as they act as guardians of the formal agenda. They also asserted that certain personages in the media can act as opinion leaders and bring media coverage to a particular issue. Government-affiliated news sources have higher success rates in becoming media agenda and have been found by a number of scholars to be the most frequently appearing of sources at the local, state, and national levels.