The US elections serve a similar purpose to that they served in the Soviet bloc countries. This purpose is not to decide policy direction, but to select which of the pre-approved party apparatchiks will preside over the policy direction decided by the ruling oligarchy. The other purpose of elections in both, the US and the Soviet bloc, is the creation of a Potemkin village of democracy - establishing a participatory ritual for the masses to create an illusion that they can influence things. Like magic or prayer to secure good crops or a successful outcome of an expedition.
Participating in this electoral ritual is perpetuating the lie it is meant to uphold i.e. that the people have say in the political process. A far more rational approach is to stop participating in it, and look for alternatives. It may or may not give the people greater say in politics, but it is rather certain that the continuation of this ritual by accepting the range of options handed down by the ruling oligarchy will not give them that say. So it makes more sense to vote for Greens or Libertarians than voting for the "lesser evil" i.e. Democrats or Republicans. This act of dissent may not tear the wall of bi-partisan monopoly right away, but if it continues long enough, it will eventually crack it - just like Eastern European dissidents eventually toppled the Berlin wall.
When I lived on the other side of the Iron Curtain, I and many of my friends made the point of not participating in elections there. Our rationale was that elections were a fraud and refusal to participate in them would expose their fraudulent nature. At one point, a group of my friends decided to go one step further and organize public boycott of an upcoming election. They were caught and arrested. At that time, I moved to another city and did not actively participate in that effort, so after spending a few nights in jail I was let go. My friends, however, were not so lucky and received prison sentences.
One may ask - why taking that risk? Why not going for the "lesser evil" and vote for the least obnoxious party apparatchik? One answer to this question may be provided by the fact that some 20 years after my friend went to jail for organizing that boycott of fraudulent elections, the system eventually collapsed and my friend became a prominent journalist in the post-communist system. His dissent paid off, eventually.
So when the US liberals try to scare me into voting for the lesser evil, my reaction is "stop being such fucking cowards. People elsewhere took far greater risks to make their voice count - they were beaten, arrested, sent to prison, and sometimes even shot. In the US, the risk is limited to having to listen to asinine political harangues coming from the presidential pulpit. This is the risk that everyone can take without jeopardizing one's safety or well being. So take it, if you really want change."
