Conservative
Type 40
Here's an NYT link about the turnout being down, for those who didn't like the first link I had.
Romney Wins, but Turnout Lags - NYTimes.com
that link contradicts your OP statement...
Consider that. Except for SC (where Newt won) turnout in GOP primaries have been down in every state.
In the first three early-voting states, Republican turnout was up from 2008 just slightly in Iowa and New Hampshire, but significantly in South Carolina, where it jumped by 35 percent.
Your link also explains the difference...
Part of the reason for the difference may be that a ballot measure, the Florida Save Our Homes Amendment, was on the primary ballot in 2008 and could have encouraged turnout even among voters who were not interested in presidential politics. In addition, the Republican race in Florida was closer in 2008 than in 2012, which usually improves turnout at the margins.