According to this story, tens of thousands of Florida voters have recently switched from being independents, to being registered Republicans or Democrats, so that they can vote in the March presidential primaries. February 16 is the deadline for registration for those primaries.
The article begins “Maybe they want to vote for …[Trump or Sanders.” Perhaps it just as well be “Maybe they want to vote against . . . [somebody].”
My wife is registered NPA and the local supervisor of elections office sent a reminder post card informing her that she needed to change her registration so she could vote in the primaries. I imagine that prompted a lot of casual voters, who might have registered NPA without realizing what it means, to take action.