I think he registered as a Democrat in New York State because the State has historically been governed by a Democrat, except for George Pataki. Malcolm Wilson was the last Republican in that seat since 1974, when Pataki beat Mario Cuomo in 1994. I can't remember if the State Legislature was split when Pataki was Governor, or he could have had a majority in both Houses when the Capital Punishment Bill was passed and he signed in. It was overturned by the Courts. But for quite a while now, Democrats have had an almost 2-1 majority in both Houses of the State Legislature. New York State has been screwed for a long time. I know because I retired from my job with New York State in 2003.
I'm sure that had a lot to do with getting his NY real estate projects through the maze of permits and approvals. The point I was making was that when the Dems thought he was one of them, they didn't have the knives out. As soon as he declared to be running for the Presidency, his Dem "friends" did a 180-degree turn.