A simple model of crowds seeking consensus for action is posited. Individual crowd members seek support from a sample of crowd members; successful ones attempt to influence the crowd toward a particular course of action. Consensus is achieved with a sufficiently reduced variability of opinions in the crowd. Independent variables are the initial distribution of opinions, crowd suggestibility and the average position of individuals seeking to influence the crowd. Outcomes of interest are whether consensus is achieved within a given time limit, the rapidity with which consensus is achieved, and the extremity of the consensus position reached. Most of the simulated crowds reach consensus within a given time limit; rapidity and extremity of consensus are considerably affected by interaction among the manipulated variables. A partial mathematical description of the model suggests that the results are nontrivial.