Things are nasty out there. Your parents probably told you this at a young age in order to prepare you for the trials and tribulations which the real world poses with a blood vengeance, but I would bet my bottom dollar they were not talking about politics.
When politics enters the equation, the already numerous unfortunate aspects of life, particularly those which present themselves during social interactions, are magnified and multiplied to an astounding degree. This is a large contributing factor to why so many politicians and political activists alike lead deeply disturbed, or even tortured, personal lives; their jobs can be highly depressing. When involved with the political process, especially as a candidate or incumbent officeholder, one must constantly be looking over his or her shoulder for anything ranging from an incessant tabloid reporter to armed madman. Honestly, can you imagine having to live in such a manner for years, if not decades, on end?
Naturally, a deep sense of paranoia will almost always develop in people who do, which is sure eventually to make an external appearance of some sort. From what I have observed, it is this profound sense of alienation that tends to lead politicians of any stripe towards either doing things which they otherwise would not, such as engaging in acts of corruption, or taking on a condescending tone while speaking to their constituents. When one is forced to live within the confines of an ivory tower such as major city halls, most state houses, and, of course, Capitol Hill, it becomes woefully easy for said individual to get drunk on his or her perceived power and cease functioning as a citizens' representative or executive officer.
This, essentially, is why so many voters become enraged at the malfeasance of their respective politicians. Unfortunately, when this warranted anger can be readily used to enact positive change, those whom I like to refer to as the "profiteers of peril" swoop in and manipulate the raw emotions of an already excited crowd. Instead of directing those deeply influenced by their proclamations to go about seeking integrity in government, they use their listeners as pawns from which a profit is intended to be made. These human vultures come from every walk of life and ideology conceivable, but most spread their dreck by way of AM radio airwaves and the Internet. Almost always assuming the identities of pundits or commentators seeking to share legitimate commentary on the day's foremost hot button issues, they rile up their respective bases to form a sort of pathological hatred for those on the other side of the political spectrum. While the frustration which should be directed at substandard holders of the public trust is indeed unleashed, it is not at them, but at ordinary people who are simply of a different political philosophy.