If the Ds from 08 had been dropped off roll in the primaries and shown up as "Us" then I think we should expect to see an increase in Us as Ds swelled their ranks. We have no evidence of that.
Second, by all polls, those Us will vote R at a 10-15% higher rate Han they will D.
Finally, most polls show that SOME Ds will vote for R at a 5-7% higher rate than Rs will vote D.
Again SOS at state level does not keep tabs of party affiliation. This is only done at the county level. Hocking for example as a county does not tabulate R/D/I compared to other counties.
The secretary of state does not maintain this data. Only the individual counties. Like Cuyahoga. So 345,000 dems registered as dems there. Did all 345,000 dems vote in 2012 dem primary? No. Many had voted in previous primaries and are still listed as dem in Cuyahoga unless they picked the republican or unaffiliated primary to vote in in 2012. Whic I doubt they did.
Again, last primary refers to the last primary that a voter participated in and not the last primary numerically, ie. 2012.
Hope that clarifies.