That is a severe flaw in all democratic systems... once the opportunity for power, greed and power are irresistible temptations.
I think that was the original idea or concept behind the Electoral College. Citizens vote for a group of esteemed and knowledgeable delegates to the Electoral College. The College then selects the people to represent us. Not only would we get higher quality representatives in Washington, but the Electoral College would act as a check and balance to make certain the representatives were acting in the best interest of the citizens as a whole (and not special interest groups.