The voting system in the United States is rather uniquely damaged with its first-past-the-post (majoritarian) elections, over a century's worth of gerrymandering that goes on strong as ever, stringent ballot access laws, public debate restrictions (which I take became stronger after Ross Perot) and so on.
It has all been meticulously crafted so that the odds are against any form of profound change, but rather to enforce the party dichotomy and have representatives maintain a comfortable status quo. The aforementioned gerrymandering strongly encourages vehement and almost parade-like, but ultimately empty and financially wasteful political campaigns, along with focusing one's efforts on leaving an impression only in certain key states and districts that are really decisive to one's performance.
Yet even people who are well versed in statistics and probability often seem to grant an exception for the insanity of voting in the United States, out of a perverse democratic ideal that ultimately isn't really there. Without some truly disruptive changes to how elections are structured (hardly a trivial matter, what with the rather fundamental chilling effect they'd have on how people have been doing things for so long), I personally find voting to be not worth one's time.