This study shows that a simple, empirically derived rule accounts well for the outcome of multi-ballot, majority-rule conventions in the period 1848-1948 and that the same rule would have enabled one to predict correctly the outcome of all contested presidential nominations since 1952 before any candidate had achieved majority support in the Associated Press'polls of delegates. The rule's success suggests two conclusions about the behavior of delegates: (1) that their guesses about outcomes are based on objective cues, similarly interpreted, and (2) that the trend in voting for candidates, in addition to the level of support they attract, is an important element of such cues. The study's findings also suggest that delegates in recent years do not contrast sharply with their predecessors in their predilection for bandwagon voting.

The research reported in this article involved tests of a model by which voting decisions can be explained and predicted. Data for the tests came from surveys conducted in five presidential elections by the Survey Research Center of the University of Michigan. Predictions made in terms of the model show it to be a good basis both for predicting the division of the vote and for predicting the votes of individual voters. Extensive analyses of incorrect predictions suggest them to be in great part the sort of errors one would expect, were voters arriving at their voting decisions in the manner described by the model. The validity of the model has implications of importance for practical politics, political history, and political theory.

In their book Non-Voting, published in 1924, Charles E. Merriam and Harold F. Gosnell reported that many persons otherwise eligible to vote had been disfranchised by Chicago's registration requirements. Their data showed that “there were three times as many adult citizens who could not vote because they had failed to register as there were registered voters who had failed to vote in the particular election” and that “entirely different reasons [for not voting] were emphasized by those who were not registered than by those who were registered but did not vote …” Their observation can hardly be said to have been influential. Until very recently most students of voting have paid little attention to the temporally prior act of registration.

Failure to do so has had important consequences. It has made it easy to discount unduly the significance of political influences on the size and composition of electorates; easy to argue unrealistically about the value of efforts to increase the turnout of voters; and easy to be puzzled about some aspects of the behavior of voters.