The real hand-wringing on both sides of next week’s special election is about voter turnout… how many, which ones, and for what issues?

He doesn’t have official predictions as to the last two questions, but Secretary of State Bruce McPherson does have a guess about total turnout on November 8: he’s pegging it at about 6.6 million voters. That would actually be the highest percentage turnout in any special election, other than the 2003 recall, since 1973.

You can ask five different people in political circles what that number will mean for the eight initiatives, and you’re likely to get five different answers.

The historic argument goes like this: low voter turnout is the norm in special elections, and low voter turnout probably skews GOP because Republicans show up to vote more often.

But even McPherson says that may not hold true this year. This time around, the real unknown is likely to be absentee voters. McPherson says more than 4.5 million absentee ballots have been requested, and about 1.8 million have already been received by registrars. If nothing else, that seems to indicate that for some voters, the 11th hour appeal by the various campaigns is too late.

Want some historical context of special election turnout by registered voters, given the 2005 prediction?