Its begins simply.
Change the way that politicians get paid:
1: Start them out on a minimum wage and keep them there as long as they are in office. Any wealth or assets they owned or have benefit from will be forfeit until after a successful terms completion.
2:Give them the ability to earn tips based on their performance.
3:Limit the amount of tips they can earn to $10 per entity, be it an individual or a corporation.
4:At the end of the term reset the tippers information so if the politician is doing a good job they can continue to work for the people.
Thats pretty much it. This method would help curb buying out politicians and would promote a system that keeps the people's well being and happiness at the forefront of their own ambitions and livelihood. It would also allow everyone in contact with the officials to see how they are doing at a glance by the quality of their life and material goods. Just my 2 iotas. Peace