In political terms, the sound bite is "a very short part of a speech or statement, especially one made by a politician." The sound bite is meant to condense an entire speech or political position into a very compressed and fixed condition. It is done as a way of summary and seeks to reduce complex and nuanced positions into the very basic and elemental.
The sound bite has changed political landscape over the last thirty of forty years. News cycles have adopted to the sound bite as being the element played repeatedly and constituting political discourse. With the emergence of the web, the 24 hour news cycle, and the controlling elements of the Twitterverse and blogosphere, the sound bite has become smaller and smaller. The soundbite is how political consultants seek to control their candidates' message. The smaller a soundbite is, the easier it is to control. The sound bite has become the norm in politics, reducing the very complex hermeneutics of governance to a nine second or less blurb that can be played repeatedly. The sound bite has changed how political messages are delivered by the elected official, relayed by the media, and understood by the voting public. It has replaced intricacy in thought and democratized it so that everyone can understand and appropriate it.