Mobilizers and Challengers

Since 1918, thirty-one new parties have entered the Dutch Parliament including nine of the twelve parties currently represented. Although the low threshold of the Dutch electoral system makes it relatively easy for new parties to enter Parliament, it does not guarantee their continued success. New party success is here explained by distinguishing between challenging parties, which contest with one or more established parties for an already-mobilized part of the electorate, and mobilizing parties, which attempt to define political issues that generate support on the basis of a new cleavage. The article evaluates key elements of the programs of new parties and, for recent entrants into Parliament, uses survey data to show that mobilizing parties develop stronger attachments among the electorate and enjoy greater longevity in Parliament than do challenging parties.