From How the Common Core Went Wrong:
... it looks like the Common Core is a back-door way for the federal government to exert tremendous influence over education. NCLB prohibits federal departments or agencies from mandating, directing, or controlling "a State, local educational agency, or school's specific instructional content, academic achievement standards and assessments, curriculum, or program of instruction." But that law proved to be a frail safeguard. Secretary Duncan funded new testing consortia in the hope, he said, that their tests would drive instruction and that they would work on "developing curriculum frameworks" and "instructional modules." Coupled with the Obama administration's Race to the Top program, its disregard for the constraints negotiated into NCLB, its expansive and troubling use of NCLB waivers, its aggressive efforts to dictate school discipline and to attack state-based voucher programs, and much else, there is cause to question how much restraint federal officials will show going forward. For instance, advocates have not created a strategy to update the standards or vet materials, prompting quiet conversations among Common Core proponents (including those at the Department of Education) about whether it wouldn't just make sense for the Department to fill the vacuum. At this point, the Common Core looks to be a standing invitation to further federal involvement in schooling.
