The purpose of this study is to evaluate several potential theoretical frameworks for understanding the social psychological processes underlying the effects of momentum. Using an experimental design embedded within a national survey conducted during the 1992 Democratic presidential primary season, I examined several potential explanations for changes in candidate preference that result from changing perceptions of public support. Findings were most supportive of an explanation based on the cognitive responses elicited by hearing about others' views. Consensus cues stimulated additional information processing and a reassessment of the individual's own position; information about mass support for candidates triggered respondents who were only moderately involved in this decision-making process to mentally rehearse potential reasons for supporting or opposing the candidates. By priming these thoughts, people's own opinions were moved in the direction of the arguments that would not have otherwise come to mind.