One reason many liberals (and others) are skeptical of the Common Core is that they have concluded that the federal government has been captured by the wealthy—especially on the issue of education—and that the imposition of the Common Core on local school districts is effectively the rich deciding that they know what’s best for everyone else.
One way that cities and towns differ from states and the nation is that a good number of them are populated largely by relatively poor people and by minorities. Supporters of the Common Core are determined to take policy-making power away from local governments. Maybe that’s a coincidence, but the effect is the same regardless.
Call me crazy, but I tend to be skeptical about proposals to disempower people for their own good.