Not voting will not magically produce an acceptable candidate. I go back and forth between voting and not voting. On a local level I know you can make an impact. The national level, not so much. The fact of the matter is the system isn't just broken, it is completely FUBARed compared to how it was supposed to be. So the question is do you try to work within the rules and try to fix it 'from within' or is it time to trash the whole thing and start anew?
Because it's the same shit every election. Stupid people vote for the lesser of two evils, get called on it, then try to rationalize how voting for the same kind of people will magically change the outcome in government.