New York

That's where that 27% comes from

The voter-registration deadline for the April 19 primary closed 25 days beforehand, when no candidate had even campaigned in New York, and independent or unaffiliated voters had to change their party registrations by October 9, 193 days before April 19, to vote in the closed Democratic or Republican primaries. This will disenfranchise nearly 30 percent of New Yorkers, including, most famously, the Trump children, who didn’t change their registrations from independent to Republican in time.

It’s easy to poke fun at the ignorance of Trump’s kids, but 3 million registered New Yorkers won’t be able to vote in the state’s primary because they are not affiliated with the Democratic or Republican parties. Election Day voter registration, which also increases voter turnout by up to 10 percent, would solve this problem.