Who votes in primaries
Voters in primaries are Democratic committee members and their friends and family. That is about it. If you look at turnout precentages, they are pathetic, usually less than 20% of the eligable voters will vote in a primary. It is better in a presidential primary, especially early in the cycle, but down ballot the turnout figures go from weak to pathetic. Once you understand this, you will begin to understand the challenge to Teachout.
Poeple who serve on political committees feel strongly about public policy, but they also feel strongly about winning. It is very hard to serve on a committee with candidates losing. It is very difficult to go door knocking for candidates who do not stand a chance of winning, take it from someone who has done it.
Which brings us to New York state Democrats. This is a group of people who are psychologically invested in Coumo. Some of them are old enough to have campaigned for his father. Some of them have been campaigning for him from his first race. All of them remember campaigning for Coumo four years ago when he was running against a Republican loon, and the Republicans have nominated another loon, so NY Democrats REALLY want to win. If they dump Coumo they will be dumping a sure winner for someone who will be much harder to elect, especially with Howie Hawkins dividing the liberal vote. (I am trying to see this from their point of view.) So Teachout has to convince a critical number of them that Coumo no longer deserves their support. The corruption issue allows her to simultaneously chip away at Coumo's supposed electability along with their psychological investement in hiim.
In addition to winning over a critical mass of Democratic committee members along with their personal networks Teachout will have to mobilize liberals who do not usually vote in primaries. It CAN be done, but it is like pulling teeth.
Which brings us to Cuomo's legal challenge to her ballot eligibility. This is how the power structure works, drive up your opponent's legal costs so that they don't have any left over to campaign with. It could work. Or, in a year that this, it could backfire. Teachout has her work cut out for her, but she could win.
The very best thing that could happen is for Teachout to beat Coumo, and Hawkins to beat Teachout. That would really get the attention of the powers that be and demonstrate that the country is serious about change.