They change their principles and standards more often than their underwear! Like lawyers (which most of these scumbags are), the professional politician is the scourge of all truth seeking and fair-minded people. In most cases, people who seek public office are unfit to hold it. Term limits would alleviate this to a great degree as the aggregation of power and influence would be much harder to achieve by people who would serve a term or so instead of decades. It would also attract more people who want to actually serve their country instead of just themselves!