For Speare the political novel is a unique genre, and the American political novel has its own individual character within the class of political novels. He was the first to insist that we not use the English or European political novel as a yardstick to measure the American political novel, since they were each working within different traditions, appealing to different readerly expectations.
Some political novels lean toward political activism, some toward art for art's sake.
Speare observes that American novelists in particular were distinguished by their zeal for reform. This activist difference could help to explain why the prejudice against political fiction is stronger in America than in other countries. References Speare, Morris Edmund. Its Development in England and in America . Oxford University Press, 1924.