Electoral behavior is growing increasingly volatile and unpredictable in many established democracies. Despite scholarly interest in the correlates of electoral volatility, we still know very little about the deep-seated reasons and determinants of the growth in electoral volatility. In this paper, I argue that a key predictor of the volatility of electorates lies in citizens’ group-based cross-pressures. Using election survey data from eight established democracies, I show that group-based cross-pressures are a powerful predictor of voters’ likelihood to switch parties and that trends volatility map onto an underlying shift towards more cross-pressures in the electorate. I then turn to investigating the sources of citizens’ group-based cross-pressures, with a focus on the ways in which parties appeal to specific sections of the electorate. I argue that when parties present themselves as the party of a specific socio-demographic group, citizens are less cross-pressured, and less likely to switch parties. These findings have important implications for our understanding of the sources of volatility, and the ways in which the interaction between parties and voters has led to increased uncertainty in electoral behavior.