The present paper attempts to explain the absence of a Green Party in America by means of comparison with the country that gave birth to the most successful Green Party so far: West Germany. In the first section it will be shown, that neither the electoral system nor other legal barriers prevent new parties from emerging in the United States. Then, the two countries will be examined from two different perspectives. First, through comparison of the politics of environmental protection it will be shown how a dialogue between the state and interest groups could be established in America, while it could not in Germany. The conclusion will be drawn that different opportunity structures define different incentives to founding a Green Party. From this finding the hypothesis will be developed that the conflictual environmental politics in Germany caused environmental concern to merge with other New Politics concerns and visions of a new state. It is from this ideology that the Green Party drew its electoral success. Due to aggregation of the environmental issue in institutional politics, this potential Green electorate did not emerge in the United States. The hypothesis will be tested empirically using survey data. Three operationalizations of the Green ideology will be employed: postmaterialism, the New Environmental Paradigm, and support for protest movements. The results deliver strong support for the hypothesis. The electoral resources for an American Green Party are weak.