(The Root) — As states grappled with ways to reinvigorate the flagging public education system, charter schools were offered up as an attractive alternative: a way to break outside the mold and offer the kind of innovative learning environment and accountability for results that is more often associated with private schools. Some critics fear that this alternative is now crowding out the public school system it was meant to supplement, creating a two-tiered system that leaves children in more traditional settings with fewer resources and options. That argument is the crux of a lawsuit filed by the NAACP and the United Federation of Teachers against the New York City Department of Education. They charge the city with favoritism toward 18 charter schools that share space in public schools. The suit, filed last month in New York State Supreme Court, claims that charter schools are getting more than their fair share of space within public school buildings and have better access to playgrounds, gyms and cafeterias. It also disputes the rationale for closing 22 failing schools, including 15 that were part of similar litigation last year by the UFT and the NAACP.