Some background information: NY-26 is a reliably republican district. Since the inclusion of the GOP in national electoral politics in 1856, republicans held this seat for 98 years straight, from 1857-1945 and since 1945, only three democrats have been elected in this district for a total of 16 years out of the last 155 years, or 10.3% of the time since the civil war:
Peter A. Quinn, from 01-03-45 to 01-03-47(2 years)
Christopher C. McGrath, from 01-03-49 to 01-03-53 (4 years)
Maurice Hinchey, from 01-03-93 to 01-03-03 (10 years), currently representative in NY-22.
Of course, the boundaries of NY-26 have changed over the years. This happens in every state, but geographically, it is pretty much where it was 165 years ago, in NW New York State.
So, without a doubt, this is a bedrock GOP district. Here is what it looks like, geographically speaking:
This CD touches on the suburbs to Rochester, but Rochester itself is in NY-28.
John McCain won this congressional district in 2008 over Obama, 52% to 46%, which means that this district swung 14% total AGAINST the national margin of +7.26 for Obama. NY-26 was one of only four NY districts to go for McCain in 2008, along with:
NY 29 (McCain 50%, Obama 48%): this was Eric Massa's district, replaced by Tom Reed (R).
NY-13 (McCain 51%, Obama 49%): this was Michael McMahon's district (he won 60.94% to 33.32% in '08), he lost it to Michael Grimm in a nailbiter in '10.
NY-03 (McCain 52%, Obama 47% - Peter King's district, he has served since 1993).
NY-26 was therefore the largest district-wide win for McCain in this very blue state.
Here the current poll data for the special election:
To the best of my knowledge, there have only been 4 polls of NY-26 for this special election. Neither side has released internal polling, which is a bad sign for Corwin: had her internals been showing a different result than these polls, surely she would have been trumpeting those results by now.
We have two separate pollsters showing Hochul in front by +6 and +4, respectively, within 48 hours of the election and both with Hochul at 42% in a three-man (four-man) race.
Some things here are statistically normal or explainable: the undecideds shrink down with time, from 9% to 5%. The implosion of the Tea Party candidate is obvious to see: he moves from 23%-24% to 12%-13%, and we see it in both new polls. His support has literally halved itself. It may shrink even more, but with the Green Party candidate bound to pick up maybe 2% plus 0.5%-1.0% for write ins, we are still looking at a total of probably 14%-15% third-party/"other" vote here. Even I take the last two polls and average them, then it looks like this:
Even if the undecideds all decide to go vote today and break wildly 80%-20% for Corwin, assuming that Davis' support remains stable, then it would still be Hochul 43 / Corwin 41 - +2 for Hochul. But usually, undecideds this late in the game do not go vote. So, assuming a stable 14.5% third party / other vote and splitting +5 for Hochul among the rest, here is how tonight may very well look, if the statistics hold:
100 - 14.5 = 85.5.
85.5 / 2 = 42.75%. 42.75% would be considered the 50 yard line, with 14.5% "other" set aside.
Splitting a +5 margin over this line means +2.50% in front of it: 42.75% + 2.50% = 45.25%:
Margin: Hochul +5.00%
The above is just an extrapolation, not a prediction, but I can see this happening today, if voting trends continue as shown in the last 3 of 4 polls.
Do we have precedent for a democratic win in NY in a republican CD with a three-man race? Yes, yes, yes:
In NY-23, after President Obama selected representative John McHugh to become Secretary of the Army, there was a special election in NY-23 to fill his slot. Democrat Bill Owens beat conservative party candidate Doug Hoffmann by +2.3% in the special election of 2009. The official republican candidate, Dede Scozzafava, pulled only 5.7% of the vote after she officially withdrew from the race. In 2010, Bill Owens retained his seat and in a strange turn of events, his third party challenger from 2009, Doug Hoffman, who became the major opponent in 2009, turned out to be a true third party challenger in 2010 (in 2009, he got 46% of the vote, in 2010 he only got 6.1%). Bill Owen's winning margin in 2010 was narrower than in 2009.
However, the end-polling for both Siena and PPP were off the mark in 2009: both predicted a Hoffmann victory and understated Owen's percentage by an average of -13 points. That being said, the sudden withdrawal of Scozzafava on the weekend, around 72 hours before the polls opened, made all of this pretty much impossible to predict. This will not be the case today.
Regardless of the results, the fact that both parties have poured an inordinate amount of money into this race signifies it's symbolic importance in the battle over the Ryan-Plan (ending Medicare).