Spitzer has been overplaying his hand, appearing like a bully against the Senate Republicans and allowing those Republicans to form an alliance with Bloomberg. I expect certain others to chime in differently, but at present he is losing that battle politically.
I can't really understand why he's giving a demoralized NY GOP anything to actually fight for at this point. Being a little more concillatory would probably have strengthened his hand (and he would have gotten more passed).
In short, the honeymoon is over. These numbers are not surprising.
Blunt's numbers may be an outlier, maybe not. People have been writing him off too quickly, like Daniels, even though I find amusing writing the conclusion for the IN race on polls that are at least 9 months old.
Bloomberg has always had an alliance with the Republican senate. Anyway.... Spitzer has already picked up 1 assembly republican seat (party switcher) and won a senate seat for the dems.