The day’s events captured years of interwoven and lingering grievances that have defined Democratic politics in New York. On one side are left-leaning Democrats like Mr. de Blasio and the Assembly speaker, Carl M. Heastie, who have traditional ties to the powerful teachers union. On the other are those backed by donors who support charter schools, politicians like Mr. Cuomo and Senator Jeffrey D. Klein, the leader of the renegade Independent Democratic Conference.

Mr. Loeb’s comment also directly hit on the long-simmering racial tensions in Albany, where Mr. Klein’s group has helped block Senator Andrea Stewart-Cousins, the black lawmaker whom Mr. Loeb attacked in his Facebook post, from ascending to the post of majority leader.

Randi Weingarten, the president of the American Federation of Teachers, who has sparred with Mr. Loeb in the past, said that Mr. Loeb, who is Jewish, “should understand the history of the K.K.K. and the history of what he said.”

She added, “One wonders what has happened with the elite in this country that they feel no consequences of using words of persecution and hate.”

The battle in Albany over charter schools, which receive public money but operate independently and often are not unionized, has been going on for more than a decade. Their supporters have fought to raise a statewide cap on charters, and increase the per-pupil allocation of state funds. Those efforts have more recently been backed by hedge fund investors: When Mr. Cuomo was preparing to run for governor in 2010, he met with a team of their representatives.