Common Core has a “how-to” implementation manual.
In this manual, on page 25, the manual discourages governors from reducing class sizes, in order to “maximize resources and share costs” for Common Core implementation.
It says: “… policies that limit class sizes in all grades hinder district efforts to achieve cost savings” and “Class size reduction policies are costly...” http://www.nga.org/files/live/sites/NGA/files/pdf/1110CCSSIIMPLEMENTATIONGUIDE.PDF (p. 25)
This manual is published by the National Governor’s Association (NGA).
The NGA, in partnership with the Council of Chief State State School Officers (CCSSO), are the “sole developers” and copyright holders of the standards.