[shawn-furyan]

You're getting into game theory territory. At present, it might be the case that voting for the third party helps to change the platforms of the dominant parties, but if this idea becomes well enough known to significantly impact voting behavior, then the dominant parties will likely pick up on it and adjust accordingly. That is to say that if they see (through polling, exit interviews and statistical analysis) that this is a significant effect, it also likely implies that the people who employ this strategy are significantly less gettable by platform changes, because a party that can taylor itself to the issues they feel strongest about will always be more attractive than the two parties that have to satisfy everyone. So you might see a Nash equilibrium develop that nullifies the effect of this strategy.

[logfromblammo]

The current equilibrium is stuck at candidates pretending to be further from the political barycenter to win their party primary, then pretending to be closer to the barycenter in the general election. Any person holding a consistent position over the entire elections cycle--which is to say anyone that has non-negotiable personal principles--is eliminated from consideration. Campaign promises are rarely honored. Nothing of genuine importance--like debt, systemic unemployment, inflation, or even just passing a budget bill for the year--is ever seriously considered.

If a new non-optimal Nash equilibrium is reached, that's fine with me, because the one we have now is absolutely terrible, in my opinion. perhaps it will inspire new political strategies that do not leave huge segments of the populace effectively disenfranchised.