Lately there has been a lot made in New York State and a little nationally about the swing of Long Island from bastion of Republicanism to a new hope for the Democrats. I have been doing a lot of research on the dynamics of NY voter numbers this swing in party numbers is rather astounding. Not only has there been a steady march to the left on Long Island, but over the past four years, the swing has been very rapid.
Between the two LI counties (Nassau and Suffolk) the change has been more rapid in Nassau. My guess is because of the expansion of the influence of NYC into it's neighbor, while the old money of the Hamptons has kept Suffolks a little behind the tide. But enough talk for now, here are some numbers (as before 'Left-leaning' is the Dems and other like-minded parties and 'Right-leaning' is Repubs and others):
Nassau County:
% Left-leaning parties:
Nov 96 - 32.00%
Apr 99 - 32.31%
Nov 03 - 35.13%
% Difference Left v. Right (+ means more lefties, - more right-wingers)
Nov 96 - -14.31%
Apr 99 - -14.31%
Nov 03 - -8.89%
% Independents
Nov 96 - 21.65%
Apr 99 - 21.08%
Nov 03 - 20.84%
Suffolk County:
Left-leaning parties (% of total electorate):
Nov 96 - 27.58%
Apr 99 - 28.32%
Nov 03 - 30.39%
% Difference Left v. Right (+ means more lefties, - more right-wingers)
Nov 96 - -17.40%
Apr 99 - -16.80%
Nov 03 - -13.49%
% Independents
Nov 96 - 27.38%
Apr 99 - 26.55%
Nov 03 - 25.73%
Graphically

In Nassau county it seems that the shift is shift is almost directly from the right to the left since the number of Independents is roughly the same, while in Suffolk county, the shift seems to be Independents moving into the left column. However, there are some under currents which are interesting in SUffolk county. In some of my reading on CD-1, it seems that the Suffolk county Republicans are coming apart and are unable to recruit fresh new talent. Recently John La Valle, a big name and young face in the county Republican party, declined to challenge Tim Bishop and there is a lot of speculation that his departure to a national office would have created a huge vacuum that the R's would have been unable to fill.
The demographics of both of these counties has changed a fair amount lately as well. While both are still predominantly white, they are because a bit more diverse with time. From 1990 to 2000, Suffolk went from 90% white to 84.6% and Nassau 86.6% to 79.3%. These numbers could account for the swing in registration numbers, but there could be other influences which I can't see with my limited knowledge.
Now, why does any of this matter, you may ask. Well, at a state level, all nine state senators from LI are Republican and the R's have a 39-23 lead in the Senate. This really makes things difficult in the legislature since the D's have a veto-proof majority in the Assembly, but are in the distinct minority in the Senate. A swing of nine senators (not all from LI since there are other competative districts) would give the D's much more leverage in the state.
On a national level, this trend make Bishops seat more secure and could bring NY-3 into play in the near future.
Alright, enough from me. The Board of Elections just posted the March '04 data and I must pile it on to my heap of numbers now.