Of Primary Importance: American Primary Elections 1945-2012

American non-presidential primary elections remain an understudied, but very important, part of our political process. In this study, I examine the state of the political science literature and provide two main contributions. First, I describe in detail all of the primary election laws used across the United States from 1945 to 2012 and analyze the consequences of using one kind of law over another. I find that, contrary to expectations, closed primary rules may result in more competitive primary elections than open primaries; furthermore, states with closed primary rules appear to get more moderate representation on average in the U.S. Senate. Due to changing legal standards, more states may be more likely to adopt in the future a "top-two" primary system which California used for the first time in 2012. I also analyze the first implementation of the "top-two." Proponents of the new law suggested that it would help elect more pragmatic legislators. I find, though a unique survey of California voters, that they sometimes achieved their goal