As the newly emboldened, Democrat-controlled state legislature rushed to pass a series of electoral reforms at the beginning of the year, one notable piece was missing: a change to New York’s peculiar party enrollment deadline.

For the 2020 presidential primary, likely to be held in April, voters will have until October 11th, 2019 to change their party registration unless Democrats in the state legislature, along with Governor Andrew Cuomo, take action. The question of whether this deadline should change at all could impact what is expected to be a fierce and divisive Democratic primary for the presidency next year.

Unlike a vast majority of states in America, New York—a closed primary state—does not allow voters to register into a party anywhere close to election time. Voters who do not belong to a party—colloquially referred to as “independents”—encounter little-publicized party enrollment deadlines that can be almost a year before the election.

In January, Democrats passed several bills long championed by progressives and good government groups, including early voting, same-day registration, and the consolidation of state and local primaries. Moving up the party enrollment deadline was never included, with no official explanation given for the omission. (Other reforms, like automatic voter registration and restoring voting rights to felons, also didn’t make the cut.)

State Senator Zellnor Myrie, the chair of the Senate’s elections committee, told Gothamist he supports changing the date from October. “While there is broad agreement within the conference that the one-year party registration deadline is too long, we are actively discussing how close to the primary the deadline should be,” Myrie said in a statement.

Every other state in America either holds open primaries or allows voters to switch parties closer to election time than New York. The 2018 Democratic primaries, held in September, came 11 months after the deadline to enroll in a party. With the 2020 presidential primary likely set for April and a state primary in June, the timeframe has been shortened slightly—but many good government groups and progressive organizations want the deadline moved into the same calendar year as the elections.

The question, as Myrie pointed out, is when exactly the deadline should be. There are bills in the state legislature that would set it at various points in the election calendar. Some Democrats are proposing a deadline to be as close as 10 days before the election, while others would like to pair it with the 25-day window newly registered voters have before casting a ballot.

Reinvent Albany, a leading good government group, has called for a party enrollment deadline to be no more than 50 days prior to an election. The window, the group argued, would mitigate fears over “party raiding”—the practice of voters ideologically unaligned with a party joining it anyway to impact the results of a low turnout primary.

“New Yorkers should not have to change their party affiliation in the previous calendar year to vote in the current year's primary election,” said Alex Camarda, senior policy advisor at Reinvent Albany. “Most voters tune in to an election just before casting their ballot, and should be able to change their party affiliation less than 50 days prior to a primary election, which is the deadline leading states with closed primaries have.”

Party-raiding is less of a concern for Democrats today, who have too many voters for mischief-makers to hijack. The much smaller Working Families Party has quietly expressed reservations about this in the past, but belongs to the “Let NY Vote” coalition that supports changing the party enrollment deadline.

Of greater concern to top Democrats could be the success of the anti-establishment Bernie Sanders, who enjoys support among progressive Democrats and independents skeptical of the Democratic Party. Hillary Clinton defeated Sanders in New York three years ago; closed primary states were particularly favorable to her.

In 2020, Sanders is likely to be a top contender in New York. This time, Cuomo is backing former Vice President Joe Biden, a leader in national polls and an establishment favorite. For Sanders supporters, trying to change New York’s party registration deadline is regarded as a key to victory.

“This is all we are doing,” said George Albro, the downstate co-chair of the New York Progressive Action Network, an organization founded by supporters of Sanders’ last campaign. “My opinion is Bernie wins the [New York] primary if independents are allowed to vote.”

New York has no plans to become an open primary state. But many Sanders backers not registered to a party expressed dissatisfaction in 2016 that they were locked out from joining the Democratic Party many months before they were ready to go vote.

For this reason alone, Cuomo and Democrats skeptical of Sanders could be wary of shuffling the party registration deadline too close to election day. Rich Azzopardi, a Cuomo spokesman, said the governor was open to discussing changing the deadline, but stopped short of making any firm commitments.

“We’ve made great progress this session to break down barriers to democracy and drag our electoral system into the 21st Century and we’re willing to discuss this, and other reforms that build upon them, with the Legislature,” Azzopardi said.