The increasing instability in the electorate and the party system forces us to reconsider the Lipset-Rokkan thesis about the frozen party system. In this approach, cleavages played a major role, but in Western Europe, this role has diminished significantly. The frequent shifts in voter allegiance call for a new understanding of the mechanisms that connect voters and parties. A reinterpretation of the concepts of a “frozen party system” or “cleavages” is not enough. We need a new theory about the strategic interaction between parties and a floating electorate.