That's true in one sense. However, pretending that everything would work out fine were it not for a few bad apples will certainly hamper attempts to keep the system running properly.
It would be far better to acknowledge that much of the behavior of a democracy results from Public Choice Theory, and so it's going to work out this way even if your favored politicians are lucky enough to win the election. With that out of the way, we can start to shore up the places where the system is vulnerable to malfeasance.
So, 2 steps:
1) Call congressmen to directly remedy problem in this particular case (I haven't done this but should, they do listen).
2) Address the problem of lobbying generally, that's a bigger discussion and every idea I have to fix it could have unintended consequences.