I also like the W. E. B. Du Bois article:

In 1956, I shall not go to the polls. I have not registered. I believe that democracy has so far disappeared in the United States that no “two evils” exist. There is but one evil party with two names, and it will be elected despite all I can do or say. There is no third party. On the Presidential ballot in a few states (seventeen in 1952), a “Socialist” Party will appear. Few will hear its appeal because it will have almost no opportunity to take part in the campaign and explain its platform. If a voter organizes or advocates a real third-party movement, he may be accused of seeking to overthrow this government by “force and violence.”