Floridians wanting to participate in the March 15, 2016 presidential preference primary had until February 16 to either register to vote or change their party registration to Democrat or Republican in order to vote in either closed primary.
Between February 1 and February 16, more than 36k Floridians became newly registered voters during the final run-up to the registration deadline. Roughly one-third of them cast ballots prior to Election Day. Some 5.4k newly registered Democratic voted (3.4k cast early in-person ballots and 2.0k mailed in their absentee ballots), and 6.1k newly registered Republicans voted (3.7k early in-person and 2.4k absentee ballots). A smattering of newly registered NPAs and 3rd party registrants also voted before Election Day.
We won’t know until next month if the 24k other newly registered voters waited to cast ballots on Election Day. We’ll never know (because the state of Florida doesn’t track this) if those who voted, or those who waited until Election Day or didn’t vote at all, opted-in to register at DMV offices or other state or federal agencies that are required to ask voters if they’d like to register. My Ph.D. graduate student, Lia Merivaki, is looking into questions like these in her dissertation. It will be interesting to see if the ongoing implementation of online voter registration across many states (and in Florida, in 2017), or automatic registration (which is already in effect in Oregon and will be in California), will lead to these new registrants voting, or deciding not to exercise their franchise.
If it’s the later, turnout rates will likely take a tip dip due to an inflated denominator of registered voters who didn’t opt when applying for their driver’s license or other services.