Certainly there exists a value X where 100-X percent of the population is not engaged at all and is little more than a source of random numbers or demographic c

Certainly there exists a value X where 100-X percent of the population is not engaged at all and is little more than a source of random numbers or demographic counts. If X is 10% then its an excellent measure of the will of the actively thinking electorate and its not the fault of the statistician that Americans don't care about politics. If X is 50% or so then there's 4 semi-motivated voters per primary voter which is getting fuzzy. Note that about 20% of the population vote in non-presidential elections and 50% vote in presidential elections. I'd propose that the delta is due to tradition and heavy social signalling to get out the vote, but that 30% don't really care and absent intense PR activity in support of voting, would not vote. Unfortunately 20% is too high to clearly support the first criteria and 20% is too low to support the second criteria. I think its really annoying that there is no mathematically trustworthy answer to is 9% enough. Annoyingly its probably good enough to not be ridiculously far off and bad enough to not be correct a significant amount of time.