A primary is simply a method by which a popular vote is used to select a party candidate for a general election. It is one method among many possibilities, but it has become the dominant approach in contemporary American politics. Today, the vast majority of states – with only a few notable exceptions – use some form of partisan primaries to select party nominees.1 And ever since the 1941 Supreme Court decision of United States v. Classic, discussed in Chapter 2, it has been clear that states have the power to regulate party primaries under their broad Art. I, §4 authority to prescribe “The Times, Places and Manner of holding Elections for Senators and Representatives.”2 The Classic Court’s interpretation was quite intuitive: As party primaries become part and parcel of an expanded process of electing Senators and Representatives, the state’s regulatory power over such primaries under Art. I, §4 must naturally follow.3