Democrats have a higher death rate ~ which sounds strange doesn't it, but it's true, and with 40% of their field voting strength being black folks, should suggest a much higher death rate than almost any other group.
So, there'd be a decline in the number of older black voters asking for absentee ballots.
Two numbers ~ one going up, one going down ~ and that would easily account for the observed phenomenon.
What you want to find is a massive drop off in the Democrat yout' vote ~ they've had another 4 years of joblessness ~ might be tired of it ~ or 'that ol' fruit don' mean nothin' ('bama doesn't care) ~ and they might just sit out the election entirely ~ which is normal behavior for 'yout'.
So, when you cut through all that, the statistics we have seem pretty staggering: Dem registrations down, huge. Absentee requests by Rs up, huge. When you throw in registration declines with underperformance, you have the makings of a pretty solid Romney victory here. Absentee requests by Dems down, significantly.
One more reason that your “black/older” theory doesn’t hold up so well: we are seeing this change/phenomenon across every single county, not JUST in urban or “black” counties, and not just in older but also in Franklin, with OSU, and Hamilton, with three universities.