I mean for an enlightened Federation we had not seen a whole lot of voter activity.
I'm sure you could find plenty of shows set in the United States, Canada, England, or other democratic nations that don't portray "voter activity" much or at all. Most shows are not exhaustive catalogs of the entire spectrum of life within a civilization. In fact, ST has shown us very little of life in the Federation proper, since it's usually about exploring the frontier.
"Journey to Babel" established the idea of a council of ambassadors voting on the admission of Coridan, though that's not a popular election. DS9: "Homefront" and "Paradise Lost" established that the Federation president was an elected position. (Jaresh-Inyo: "When they asked me to submit my name for election, I almost said no." Sisko: "Overthrowing a legitimately elected President and giving Starfleet direct control over the government? It sounds like a dictatorship to me, and I'm sure I'm not the only one who thinks so.")
Actually the book to check out is the one that precedes that, A Time for War, a Time for Peace
. That's the book that actually portrays the presidential election process in the Federation; AotF is about the first year of President Bacco's term in office.