"Although the Casey joint opinion retains what it considered to be the essential principles of Roe, it explicitly rejects the trimester framework as a means of testing the constitutionality of state abortion regulations. In doing so, Justice O'Connor first explained that "the Court's experience applying the trimester framework has led to the striking down of some abortion regulations which in no real sense deprived women of the ultimate decision" of whether to terminate a pregnancy. Justice O'Connor made this conclusion, however, without citing any specific cases or abortion regulations. Second, Justice O'Connor stated that in practice the trimester framework undervalued the substantial state interest in potential life throughout pregnancy by treating all government interference before viability as unwarranted. Once again, these arguments demonstrate the joint opinion's preparation for a move toward a standard more in line with a rational basis review by highlighting the substantial nature of the state interest and the notion that a woman's ultimate decision can be restricted as long as it is not deprived in some "real sense”."