A lot of folks want to blame Romney’s loss in Nevada on voter registration, pointing to the Democrats’ well-publicized registration efforts over the three-month period leading up to this year’s general election. Alas, the numbers just don’t back that up. Consider the following:At the close of registration in 2008 in Nevada, there were approximately 531,000 “active” registered Democrats. At the close of registration this year, there were approximately 527,000 “active” registered Democrats. So over a period of four years, the number of active registered Democrats in Nevada shrunk by 4,000.Meanwhile, at the close of registration in 2008, there were about …