Following his more conciliatory remarks on charter schools at Riverside Church on Sunday, Mayor Bill de Blasio told WNYC’s Brian Lehrer he believes there is room for charters to grow in New York City, even though he blocked three schools that former Mayor Michael Bloomberg wanted to open this fall.

De Blasio acknowledged he didn't do a good job explaining his decision-making process. Unlike the previous mayor, he said he was more concerned about the impact one of the charters would have on other students.

“I think the bottom line is the Bloomberg administration was rushing and they were willing to cut some corners,” he said, referring to the Success Academy middle school that was supposed to open inside a Harlem building housing P.S. 149 and a program for children with special needs. “Clearly when we looked at what we do to the special ed kids, it was quite clear there would be less capacity for special education, that the programming there would be undercut.”

Success Academy CEO Eva Moskowitz has since challenged this in lawsuits, claiming her school had every right to the location but was blocked by politics.

De Blasio said charters can be co-located with regular public schools so long as the process is more "respectful and mindful.”

Supporters of charter schools have been running ads targeting the mayor, and Gov. Andrew Cuomo has stood with the charter lobby. This all comes at a time when the mayor needs the governor to back his proposed expansion of pre-k and after-school programs in the new state budget, due April 1. Some state lawmakers want to prevent de Blasio from charging rent to charters, as he promised during the campaign, and from preventing co-locations.

De Blasio said he agreed that privately managed charter schools have tried new things and gotten higher test scores in some cases. But he said not everything they do could be applied to the rest of the school system.

“A lot of folks in the charter movement will tell you they understand some of what they are doing cannot be scaled up to the whole school system,” he explained. “So in effect its rarefied in many instances. That doesn't mean there isn't something to learn, it doesn't mean we don't value with them and want to work with them.”

He noted that many charters have longer school days, and said his proposal to expand after-school programming for middle schoolers would benefit more students.

Listen to the whole segment, which also touched on teacher retention and subway panhandling.