I suggest a contract a presidential elect signs with The People, WHERE it states a punishment will take place if the contract is not fulfilled. Empty promises, no more. Make the punishment grand enough with additional immediate impeachment clauses that force an honest candidate to act. No-body would want the job unless they truly believed in their country and their promises, not simply to appeal to the people and act as puppet elect. Boot all lobbyists out of influence potential, prevent politicians from accepting bribes, pay them WELL enough already, and eliminate ones that accept any bribes from their positions. Get rid of monetary corporate influence from government, it only fuels corporate agenda. Realign country with sovereign policy and break world influence upon policy.
There are many details to iron out, but that's a small portion of general ideas.