If that seems completely backwards, it's because it is, in comparison with the present way of doing things. Right now, people have to stand for office. Well, if someone wants the job, then it's fairly safe to say that they want it, at least in part, for some personal gain. After all, the cynical part in our society is always quick to deride the politician as self-serving scum, and current events have done nothing but reinforce that notion.
If, then, all candidates for elected office who put themselves forward can be dismissed as too vested in the outcome and the powers of the office, how do we select candidates?
At first glance, one might think that a sort of middle-school-esque "nomination system" might work. That is, until one realises that this isn't middle school and that open nominations encourage just as much, if not more, corruption and inside dealing as self-nomination. The only advantage I see to nominating people is that we know who their allies will be.
No, I believe that we have the best system for nominations as we can get right now. The best way to decrease the amount of corruption in politics is to provide for more oversight. "What if the overseers are corrupt?" Well, we'll just have to trust to the law of averages that if we have a large enough oversight board, at least one person on it will not be corrupt. Now that is cynicism. Trusting the fidelity of a nation's political system not to people, but to a statistical law.