Compare and contrast the functions and tactics of political parties and interest groups in America today. Do they both serve the same functions? Do

Compare and contrast the functions and tactics of political parties and interest groups in America today. Do they both serve the same functions? Do they have different roles? Why is it that political parties seem to be on the decline while the numbers and membership of interest groups increase? What does this decline of the former and increase of the latter say about the state of American politics today?