This book is essentially a sociological analysis of voter participation. The author shows that youth are more or less effectively socialized to treat voting as a civic duty, they carry their normative behavior into adulthood, homogeneous communities favor voting as a civic duty while heterogeneous communities foster voting as a political instrumentality. The volume and quality of the data are excellent, and the author's analysis thorough and credible. The author's suggested policy advice is that schools should do more to promote political participation and foster an ethic of civic duty. This may sound like a throw-away, but it probably is good advice.
I would like to have seen some light shed on the correlates of voter participation---what kinds of people participate for what reasons. Also, are participators higher or lower in happiness, mental health, length of job tenure, success at work and marriage, and so on.
Like many political scientists, Campbell cannot seem to understand (though he presents the argument early in the book) that even voter participation with politically instrumental motives ("I am voting because I want this or that candidate to win/lose") is deeply altruistic. One voter can never make a significant difference in an election with more that 1000 voters participating, so people who claim to be voting for instrumental reasons are simply not correctly explaining their behavior.
How should we interpret politically instrumental voting? Probably, individuals of this type vote to express personal feelings in a socially acceptable venue, and/or they consider their behavior a contribution to an in-group with which they identify ("we people who believe in x"). Possibly, it would be difficult credibly to hold a strong opinion concerning certain public affairs without demonstrating some costly commitment, of which voting is one form.