The political agenda can be influenced by multiple institutional and non-institutional actors acting independently or concurrently, including
political office-holders,
interest groups,
social movements, and other entities. Although these actors, most notably the media, often have an effect on the political agenda, these results are not always immediate. Time lags in the political agenda can last from a few weeks to several months.
Political and policy elites The political agenda is essentially defined as what governmental officials find important to discuss. Those closest to the policy process have the biggest control on what issues reach the political agenda. They are the ones with the most power to decide which ideas or issues have the most importance, and which ideas or issues are unimportant. Political elites also have considerable ability to determine how issues on the political agenda are debated, in terms of order, framing, and substance. For example, the
President of the United States, has the power to make treaties, appoint
ambassadors, appoint justices of the
Supreme Court, and shape public and institutional debate around these actions. These types of powers ultimately shape what issues reach the political agenda and how they are discussed thereafter. Many other important activist groups, like those oriented towards
human rights and social
justice, campaign for broad ideals. These groups work to put continuous pressure on government leaders that shape the agenda. If enough pressure is exerted onto political leaders through activist groups, it can change which issues and ideas ultimately reach the political agenda. For example, the
American Bar Association (ABA) and the
American Medical Association (AMA), usually try to influence politicians on professional jobs. Examples of think tanks that promote a certain political perspective onto the political agenda are the
Heritage Foundation and
American Enterprise Institute which are highly conservative. On the other side, the
Center for American Progress, are more liberal with their motives. The Mabo decision by the High Court in 1992 which overturned previous laws about establishing native titles is an example of this. Hajo B Boomgaarden and Rens Vliegenthart write on the media's relation to political agenda in their article
Explaining the rise of anti-immigrant parties: The role of news media content. In this article they study the media coverage on anti-immigration in the
Netherlands for the period of 1990 to 2002 and found that it directly relates to the success of anti-immigration populist parties such as Centrumdemocraten (CD), the Centrum Partij (CP), and the Lijst Pim Fortuyn (LPF) during the same time period. Their analysis used the importance of news media as the explanatory factor of why anti-immigration gained prevalence on the political agenda, while controlling for other real world factors and developments at the time such as the influence of the economy, immigration, or the leadership of then President
Pim Fortuyn. This was done by conducting a content analysis of five of the most popular Dutch national newspapers. The empirical results showed support of anti-immigration was around 4% in 1994, and rose to 16% in 2001 during the same time that media coverage of anti-immigration was at its peak. This means, the test showed that media content can be held at least partly responsible for the rise of anti-immigrant parties in the Netherlands and the changing of the political agenda in this way. The end conclusion was that most of the time presidents react corresponding to fluctuations in media attention on an issue. It too showed a relationship between the media and political agenda.
World events When something unexpected happens it can force the political agenda to change immediately. For example, when
Hurricane Katrina devastated New Orleans, the United States responded by sending emergency disaster aid to the affected areas and several organizations set up donation funds. After the
9/11 World Trade Center attacks, national security and anti-terrorism efforts became a top priority for the government. Big world events can change the priority of certain issues for the public. When big world events (i.e. disasters/tragedies) occur they are often followed by a policy response as well, and so what issues and ideas reach the political agenda are sometimes changed simply due to what happened in the world. == Varying theories on who sets the political agenda ==