You don't. They are human too, tempted by greed or afraid of what happens to them when they are done serving. It goes along with WANTING to be in a political p

You don't. They are human too, tempted by greed or afraid of what happens to them when they are done serving. It goes along with WANTING to be in a political position, if one did not want the money or the power trips then that one is likely also a nutjob of zealous flavor. The flaw with this logic, is that the ideal politician does not want the job, this could make them incorrigible or careless. It also means almost nothing gets done by the incorrigible politicians (which I have to see as a good trait for any government) and poor quality work is done by the careless ones.