The term political campaigns conjures up visions of candidates running for elective office: signs and billboards and TV advertisements, outlandish claims and promises, negative personal attacks, rallies, and hoopla. But there are also other kinds of campaigns: those for or against constitutional amendments or local ballot initiatives; for or against particular policies (gay marriage, gun rights, civil and voting rights, etc.); those seeking to sway the hearts and minds of people to support an existing regime or to demand a new one; and the ultimate political campaign, war.

What all political campaigns have in common is the intent to persuade: for or against a candidate, a policy proposal, a power structure. The sole raison d’être for any campaign is to convince voters, or the public generally, ...