By voting for the lesser of two evils you just get more evil. The democratic party decided to move to the right after the devastating defeat of George McGovern. The democratic party decided to move even further to the right after the Reagan Revolution. But both Nixon and Reagan’s victories were due to an anomaly of the times. They were caused by the backlash to the culture wars of the sixties. Culture wars that are basically over now- and, interestingly, McGovern’s side has won.
It is no longer a social stigma to have sex before marriage- or to live together, women are universally perceived as equal to men, blacks have the same legal rights as whites, people can look and dress however they want, Gay marriage is legal all over the US, marijuana will soon be legal all over the US, abortion is still legal. There is still work to be done in these areas (especially economically). There are, shamefully, still pockets of disagreement with these new social paradigms- but they are now small pockets instead of a majority backed by the law of the land.
These cultural changes occurred in spite of the nation’s shift to the right politically and economically. By the time Clinton was elected the democratic party had become a right wing party when it came to economics and militarism. This was consciously and purposefully done to court big-money.
As they moved rightward they saw that they got elected so they continued to move to the right. By voting for them just because they’re better than the other party, you force them to the right. You make them the lesser of two evils instead of making them the good.
What if people voted for what they wanted instead of the lesser of two evils? Well the greater of two evils might get elected for awhile; but the lesser of two evils would shift to the left since they would see that staying on the right wasn’t getting them elected anyway. It would take awhile but eventually the democrats might become the party of the left again (or one of the parties to their left might gain enough votes to become wide-spread) as the country gets fed up with the greater of the two evils being in power.
I’d rather vote for what I believe in (true left-wing politicians) even if they can’t win. I’d rather have the slightly worse right-wing party in office for awhile to get a more left-wing party in office later on. The lesser of two evils is still evil. If you vote for the lesser of two evils- you guarantee that evil is what you always get.