Everyday, the USA and her people evolve. In order to have better leadership, the leadership itself must also evolve with the people. By setting term limits to all government positions in Washington DC(house, senate, congress, etc..), this allows fresh faces and ideas in to these positions and allows any American the chance to serve his or her country in this position.
There are government officials now that can barely walk and have held their positions for 40+ years! People that were alive when the Mobsters were running the show.. How is this fair and just to the people? We have tons of super qualified, young, ambitious people that can serve just as well.
By cycling these positions, this may tend to drive away corruption and give "We the people" a voice for once.