Some of Bernie Sanders’s biggest supporters may not be able to vote for him in New York’s primary on Tuesday. Unaffiliated voters are a big share of Sanders’s support, but New York makes it hard for voters to register for a party at the last minute. For example, Erica Garner, daughter of Eric Garner and a Sanders supporter, can’t vote in the Democratic primary because she didn’t change her party registration in time to qualify. It’s an issue for Republicans too: Some high-profile Donald Trump supporters — or at least two of his kids — won’t be able to partake in the fun. New York’s deadline for switching party registration was Oct. 9, 193 days before the primary. I wanted to know if a party-switch deadline six months before a primary or caucus was as unusual as it sounded, so I went through every state’s election board website to see.
Twelve states and the District of Columbia have earlier deadlines to switch parties than to register for the first time,2 but only two of them, Kentucky and New Hampshire, had cutoffs to change parties (for those already registered with one) more than 100 days before their primary or caucus.3 I looked only at states without open primaries or caucuses.4 In open primaries, any voter can weigh in on the presidential candidate nomination process for either party.
Some states, such as Wyoming and Maine, allow new voters to register and pick a party up to the day of the election but require people who have previously voted to change parties about two weeks before the election. That kind of cutoff may be confusing to residents who assume that same-day registration means you can also make same-day registration changes. However, it is still a more modest deadline than many states set for both new voter registration and updates.