From Steven Shepard’s Politico post “How New York Will Be Won“:

In the Democratic presidential primary, about half the vote will come from New York City’s Five Boroughs — a percentage that increases to nearly three-quarters of the vote when the entire New York media market is included.
By contrast, the city accounted for only 13 percent of the votes in the 2012 Republican primary. And of the 34 counties across the state where registered Republicans outnumber Democrats (out of 62), only one — Putnam County — is located near New York City.

Ford Fessenden and Sarah Almukhtar note in their New York Times article, “The Battle for New York’s Key Voting Blocs in the Primaries“:

Whites with money on the Upper West Side, in Chelsea and in brownstone Brooklyn are the Democrats’ liberal base. They have opened their wallets for Hillary Clinton — she has a 10-to-1 advantage over Bernie Sanders in contributions — and they turn out reliably.
The voting center of Democratic New York in high-turnout elections is farther east, in black neighborhoods in places like central Brooklyn and southeast Queens. Mrs. Clinton has done well here in the past, even in 2008 against Barack Obama.
“If Hillary Clinton were running against someone other than Barack Obama in 2008, she likely would have swept the city,” said Steven Romalewski, mapping director at the CUNY Graduate Center.
The most liberal Democrats in New York could be the gentrifiers in hipster Brooklyn, but there aren’t many of them…Mr. Sanders raised more money than Mrs. Clinton in Williamsburg, Greenpoint and Bushwick, Brooklyn, but this territory is split among three congressional districts, making it difficult to translate votes into delegates.
Despite Mrs. Clinton’s success throughout New York in 2008, Mr. Skurnik says Mr. Sanders has a shot in rural upstate districts, where “despite popular belief, Democrats are not farmers, but are instead teachers and government workers.”

Pre-election polls have not exactly had a great year in the primary season. But it is significant that Clinton leads Sanders by double digits among eligible New York Democratic voters in key polls. As Jonathan Easley writes at The Hill that “Surveys in the state have consistently shown Clinton holding a lead of somewhere between 10 and 17 points in the state. Sanders has yet to climb to within single digits of Clinton in any poll of New York so far this cycle.” Fivethirtyeight.com’s NY Democratic primary forecast has a weighted polling average of 21 polls show a 53.2 percent average for Clinton, vs. 39.7 percent average for Sanders.
But Sanders, notes Jose A. Delreal in the Washongton Post, “has drawn tens of thousands of supporters at rallies in recent days.” Barring an upset, it will be the size of Clinton’s margin of victory that pundits will be watching to assess the Sanders and Clinton campaigns’ momentum going forward.
All other factors being in a predictable range, what may prove to be the most interesting statistics coming out of the New York primary are the raw vote tallies of Clinton and Trump