I thought about the Tenth Amendment, but I forgot after writing in comment# 1.
Noobie here. Keep in mind that the States created the Federal government. The “creator” is always greater than the “created.” The States should never go hat in hand to a Federal court where their State sovereignty is involved. Therefore, Cuccinelli should have simply informed Washington that since the science is flawed and has a very negative impact on Virginians then Virginia will block any new EPA regulation. End of story.