I said that wrong, the turnout WAS lower for 2012, but Romney did increase his share by less than a million over McCain in 2008.
As far as how it broke down I don’t know, Romney did easily win the Independents, yet still lost, it might have been conservatives who stayed home, possibly because of Romney coming out as pro-choice, and running pro-choice ads in battleground states.
And probably received 100% of the deceived MORMON vote...
I use the age and racial data provided by NEP, which is used by all major news networks, AP, and the NY Times.
You may be using some parts of the Census Bureau election data, which can be substantially different.
According to my math:
2012 - Obama’s white vote went down 5.5 million.
2012 - Romney's white vote went up 1.4 million compared to McCain.
2012 - Total white voters went down 4.2 million.
Many folks at Free Republic insist that 4 million Conservatives stayed home in 2012.
I don't think the data supports that conclusion.
I think it is much more likely that 4 million white Obama supporters stayed home in 2012.
A definitive answer to this question can actually be found in the raw NEP data.
But that's behind a pay wall.