Political public opinion can be expressed either positively or negatively. A positively expressed attitude endorses a particular policy from among a range of options for a given issue. Favoring a reduction in defense spending or a prohibition of late-term abortions are both positively expressed attitudes. A negatively expressed attitude on an issue indicates what one does not want to happen and is difficult to portray as crisply. With respect to defense spending, for example, one might feel: “No increase is needed; any more than a slight increase would be damaging; drastic cuts are also unreasonable; even some moderate cuts are worrisome.” Here one rules out disliked positions and is left with a set of options ranging from inoffensive at worst to desirable at best. Politicians retain some latitude to endorse policies from within this range of non-objectionable options without alienating the voter.

Whatever virtue negatively expressed attitudes may have – such as more accurately reflecting the way people think about many issues – they are messy, disturbingly provisional, and difficult to summarize across persons. Academic and political observers have avoided them; while recognizing that negative information may play strong roles in determining political attitudes (Lau, 1982), they construct the attitudes themselves as positively expressed. Elsewhere (Diamond and Cobb, 1996), I argue that modeling political attitudes in this unwieldy, imprecise, negatively expressed fashion greatly aids our understanding of real voters' conceptions of real candidates.