Using an original dataset of state party bylaws, this dissertation examines the institutional role of state political parties in congressional primaries. Specifically, I consider how representative state political parties are of the general public, whether the varying levels of representation found in each state party influence who runs for Congress, and whether state political parties are able to influence levels of electoral competition through provisions of their bylaws. Overall, I find both state Democratic and Republican parties vary in the extent to which they prioritize gender representation and youth representation in their state central committees through their party rules. However, these rules only seem to influence the candidate emergence process during Democratic primaries. Specifically, in 2018, Democratic women were more likely to run for the House of Representatives when representing a state party chaired by a woman and when representing a state party which granted party committee membership to an allied women's group. Similarly, state Democratic parties were more likely to nominate younger candidates for the House of Representatives as the number of youth party members in their state central committee increased. Beyond candidate emergence, I find state party rules also influenced levels of electoral competition during the 2018 congressional primary elections, albeit differently for each party. State Democratic parties were less likely to see divisive primaries when they avoided policies that required the party to remain neutral during contested primaries. In comparison, state Republican parties were less likely to see divisive primaries, and also saw fewer primary candidates in general, when they guaranteed ex-officio party membership to their co-partisan elected officials
