Politico said the day after the election in 2008 that 130 million voted. Wikipedia says the final result was about 131 million. So these numbers probably won’t go up.
Have we seen numbers to show the base stayed home? It’s possible that Obama’s negative campaign drove down turnout of independents who disliked Obama but thought Romney was an unacceptable alternative.
Some of the negative campaigning was trumped-up garbage like the war on women. But some of it was extremely predictable and was used against Romney in the primaries, like his flip-flopping (Romnesia) and his record on Bain Capital, easily spun as someone who lays off workers, as shown by the ads Newt used in South Carolina.
Maybe Kevin Madden shouldn’t have dissed Sarah a few days before the 2008 election and suggested that McCain should have picked someone to be VP “who has been a governor for a long time”. Sarah’s support probably could have put Mitt over the top.
http://townhall.com/tipsheet/amandacarpenter/2008/10/28/romney_supporters_trashing_palin