cant u just look at the percentage of voter turnout and figure that out
The problem here is that voter turnout in the US is an inexact science, as there is no universal or near-universal registration.
Most media sources use "voting age population" for an approximation, but of course that includes noncitizens - their share has risen since 1984; Reagan won a larger share of the Voting Age Population than Obama. (There is also the issue with the lack of voting rights for convicts and, in a declining number of states, for some classes of ex-convicts.)
