When candidates in primary elections are ideologically differentiated (e.g., conservatives and moderates in the Republican party), then candidates with similar positions affect each others' vote shares more strongly than candidates with different ideological positions. We measure this effect in...

One of the most widely discussed phenomena in American politics today is the perceived increasing partisan divide that splits the U.S. electorate. A central contested question is whether this diagnosis is actually true, and if so, what is the underlying cause. We develop a model that relates the...