5.diversity and pluralism 6.republican form of government and democracy These are key and mainstream American political values.Holding opposite values is said to be un-American.However,we should treat these values as ideals.The American political system is still evolving and self- improving.5. diversity and pluralism 6. republican form of government and democracy These are key and mainstream American political values. Holding opposite values is said to be un-American. However, we should treat these values as ideals. The American political system is still evolving and self￾improving