There should be an established framework for politicians to make *binding* pre-election promises. Perhaps some sort of federal filing form, similar to "registering" to be on a ballot. Along with their registration, they should be required to file a document of what things they truely promise to stick to, if elected.
Then, if they are elected, and violate those promises.... They should be directly, and instantly, impeachable, soley on the grounds of that document. Due to "breech of contract", if you will. Reguardless of whether the office is sheriff, mayor, governor, or president of the United States of America.