The New York World/Center for Urban Research analysis of the electoral impact of the boundaries for proposed state Senate and Assembly districts relied on 2010 election data posted on the website of the state Legislative Task Force on Demographic Research and Reapportionment (LATFOR). Our goal was to determine the results of state legislative elections held within the new districts if voters cast their ballots in the same way they did in the previous state legislative election, in 2010.
We analyzed election results at the level of voter tabulation districts, or VTDs, which are several blocks in size and typically cast no more than a few hundred votes in state legislative races. We mapped the VTDs onto the new lines proposed by LATFOR, then added up the votes of all VTDs that fell within a proposed district to determine its outcome.
In order to assign the VTD-level vote tallies to LATFOR’s proposed districts, the Center for Urban Research used geographic information systems software to match VTDs with the current and proposed legislative district lines. Most VTDs are fully contained within both current and proposed legislative districts, but some crisscross district lines. The Center identified the geographic center-point of each VTD and assigned it a Senate and Assembly district corresponding to that location. In the few instances in which VTDs crisscross legislative districts, this allocated all of a VTD’s votes to a single legislative district rather than splitting them across multiple districts, but the results show little or no deviation from actual Board of Elections vote counts in those districts for 2010.
Because New York has “fusion” voting, in which candidates may run on more than one party line, our tally added together all votes each Democratic or Republican nominee received in 2010, including votes they accumulated from other parties’ ballot lines, such as the Conservative and Working Families parties.
– Sasha Chavkin and Michael Keller, The New York World, and Steve Romalewski, Center for Urban Research