I love how gullible people (mainly americans themselves) believe that game ain't dirty in USA... LOL
The candidates who would cause serious losses in power and/or money to powerful instances have no chances to win. That's for sure.
Imagine how America's only remaining industry, 'defense' industry would suffer if a man who wants to concentrate on domestic issues (which are severe) instead of bombing small, unarmed countries was elected as President !!
Political system is so corrupt and connected to too powerful non-governmental instances, that it's impossible to separate them without major overhauls, which would cost blood and tears and years of struggle.