A smart friend in Albany tells me:

The identity of our new senator is raising plenty of eyebrows around New York State, in both parties. The Village Voice wonders: “Is Gillibrand Too Republican to Replace Clinton?” But the threshold of offenses a Voice reader would define as “too Republican” is too low to be visible to the naked eye in most of the country. Keep in mind that Gillibrand’s upper Hudson Valley district, which takes in Albany’s eastern and northern suburbs, has the heaviest Republican enrollment overlay in New York State. Her win in the Democratic landslide year of 2006 was something of a fluke, aided by the very conveniently timed leak of a state police report about a domestic violence incident involving the incumbent Republican, who happened to be feuding with the D’Amato-Pataki gang, to which Gillibrand happened to have a family tie (her father is a longtime D’Amato crony whose significant other, for a time, was Pataki’s communications director, who was also D’Amato’s former spokesperson). Indeed, as soon as Gillibrand surfaced (more or less out of nowhere) as a candidate for the Democratic nomination in 2006, there was widespread speculation in local political circles that D’Amato and Pataki had put her up to it. In a further twist, she stood for a second term last year against a well-funded challenge by Alexander “Sandy” Treadwell, who is one of Pataki’s closest friends and the former state Republican chairman. Surrounded by a crack team of consultants from the Democratic Congressional Campaign Committee, Gillibrand won handily.
But Gillibrand’s political ancestry is true-blue Democrat. Her grandmother, Polly Noonan, was a powerful figure in Albany’s fabled O’Connell Democratic machine; Noonan was, as the local newspapers used to put it, a “confidante” of longtime Albany Mayor Erastus Corning 2d, whose tenure in City Hall ran from the early 1940s to the early 80s. Tomorrow’s headline in the Albany papers might just as well be “Local Machine Princess Makes Good.”
Gillibrand is reportedly a member of the Blue Dog Coalition, but this may not reflect a personal philosophy so much as the opportunism that has always been the lodestar of Albany machine Democrats (and, for that matter, of D’Amato Republicans). Certainly there was little sign her vote against the bailout package was as thoughtful and principled as, say Eric Cantor’s; she was, remember, one of 95 Democrats, including many vulnerable freshmen, to oppose a bill that most voters in both parties saw as a giveaway to irresponsible bankers.
Prior to 2006, Kirsten Rutnik Gillibrand was a lawyer-lobbyist who was virtually unknown even in the capital region. Until a few weeks ago, it’s safe to say that very few people, even those who voted for Kirsten Gillibrand, had ever imagined her as a U.S. senator. But given what we’ve seen in New York politics over the past year, nothing comes as a surprise anymore. As a friend puts it: ”It’s a reflection of everything going on in Albany these days, for which the operative phrase is ‘circus ticket’.”

He adds:

With Gillibrand’s exit, the race for the GOP nomination in the special election for her Republican-leaning seat will be a scramble among several well-known candidates, including Treadwell, former Assembly Minority Leader John Faso, and current Assembly Minority Leader Jim Tedisco. The winner gets to hold the seat for two years before the Democratic legislature redistricts it out of existence.