"In the plurality's view, the viability testing provision imposes a burden on second-trimester abortions as a way of furthering the State's interest in protecting the potential life of the fetus. Since, under the Roe framework, the State may not fully regulate abortion in the interest of potential life (as opposed to maternal health) until the third trimester, the plurality finds it necessary, in order to save the Missouri testing provision, to throw out Roe's trimester framework. Ante at 492 U. S. 518-520. In flat contradiction to Roe, 410 U.S. at 410 U. S. 163, the plurality concludes that the State's interest in potential life is compelling before viability, and upholds the testing provision because it "permissibly furthers" that state interest. Ante at 492 U. S. 519."