Answer: Unions–and organizations getting money from them.
From the NY Post:
Five of the Top 10 lobbying and campaign-donating entities in 2009 were, broadly speaking, part of the health-care cartel. No. 1 was the Healthcare Education Project — an unholy alliance of the Greater New York Hospital Association and SEIU 1199, the health-care workers union — which spent $3.8 million in an ad campaign against mild cuts suggested by the governor.[…]
Separately, the hospital association spent another $2.1 million and 1199 tossed in $1.5 million in lobbying activities. Also in the Top 10: the teachers unions — the city’s United Federation of Teachers and its parent New York State United Teachers (No. 2).
Check out the original information from the New York Public Interest Group HERE.