"All I will say is that there are particular features of the American constitutional system that renders a third party futile - at best"

This quote by Todd Gitlin recommends that the American constitutional system makes it hard for a third party to be successful. He implies that the system is designed in such a method that it makes it difficult for a third party to acquire traction and be successful. This could be due to the two-party system that is entrenched in the American political system, that makes it difficult for a 3rd party to get enough assistance to be successful. Additionally, the electoral system in the United States is created to favor the two significant celebrations, making it difficult for a 3rd party to acquire sufficient votes to win an election. For that reason, it is likely that Gitlin is recommending that the American constitutional system makes it challenging for a third party to be effective, and at finest, it is futile.