A key implication of our notion of legitimacy is that legitimacy can require omitting one or more alternatives from the decision sequence. In this chapter, we delve a little deeper into this somewhat perplexing implication. Specifically, we describe its relationship to specific procedural characteristics that can be broadly described as restrictions on scope – that is, standing rules precluding the consideration (or, perhaps, comparison) of one or more alternatives. Such restrictions are common to political and social institutions. In this chapter, we focus first on the U.S. House of Representatives and discuss a key way in which the scope of legislative business is structured in that institution: germaneness. We then turn to the related phenomena of single-subject provisions, a class of rule that limits the scope of statutes.

Before moving to detailed discussions of institutionalized restrictions on the scope of discussion, it is important to note that this chapter focuses exclusively on legislatures. This is by design: the other two chapters in which we discuss real-world institutions focus on the decisions of unelected government officials (judges and bureaucrats). As discussed in Chapter 4, the decisions of popularly elected officials are imbued with a higher level of innate legitimacy than those of unelected officials. Precisely because of this, institutional rules such those discussed in this chapter – rules that both constrain legislative autonomy and are consonant with our theory of legitimacy – are particularly interesting. Within the context of our theory, the germaneness requirement in the U.S.