Optimates and populares are political terms from late-Republican sources referring to a political divide between supporters of the senatorial authority and champions of popular liberty and popular demands. The precise meaning of these terms and the nature of the divide to which they refer have long been disputed among scholars. Though the sources sometimes speak of partes in this context, it is obvious that the Republic had no “senatorial party” or “popular party” in anything like the modern sense of the term. Based on this, and on the tendency to describe Republican politics as wholly dominated by personal and family connections and rivalries within the ruling class, the significance of the political divide in question has often been dismissed or minimized.
However, the sources repeatedly indicate that this divide could, at least on occasion, play an important role in public affairs—alongside other factors including personal ties, family alliances, and oligarchic cliques. One of the consequences of the fact that the labels optimates and populares did not signify a formalized affiliation was that their usage was highly flexible, often inconsistent, and certainly open to manipulation. Pro-senatorial politicians might claim, in public, to be “true friends of the people (populares),” unlike their allegedly demagogic anti-senatorial opponents. But terms that are meaningless or insignificant to the wider public are of little use to political manipulators—who have in any case no guarantee, in a competitive political system, that their manipulation, rather than a rival one, will always carry the day. As long as Republican politics lasted, the optimate/popular divide appears to have been a significant feature. Its relative importance, and specific import, must have varied greatly from case to case, and should in every case be assessed individually.