educational opportunity in the United States has fallen short of completion. In the view of various liberal scholars, the election of Richard Nixon in 1968 meant that the executive branch was no longer behind the Court's constitutional commitments. Also, the Court itself decided in San Antonio Independent School District v. Rodriguez (1973) that the Equal Protection Clause allows—but does not require—a state to provide equal educational funding to all students within the state. Moreover, the Court's decision in Pierce v. Society of Sisters (1925) allowed families to opt out of public schools, despite "inequality in economic resources that made the option of private schools available to some and not to others", as Martha Minow has put it. American public school systems, especially in large metropolitan areas, to a large extent are still de facto segregated. Whether due to Brown, or due to Congressional action, or due to societal change, the percentage of black students attending majority-black school districts decreased somewhat until the early 1980s, at which point that percentage began to increase. By the late 1990s, the percentage of black students in mostly minority school districts had returned to about what it was in the late 1960s. In Parents Involved in Community Schools v. Seattle School District No. 1 (2007), the Court held that, if a school system became racially imbalanced due to social factors other than governmental racism, then the state is not as free to integrate schools as if the state had been at fault for the racial imbalance. This is especially evident in the charter school system where parents of students can pick which schools their children attend based on the amenities provided by that school and the needs of the child. It seems that race is a factor in the choice of charter school. Application to federal government By its terms, the clause restrains only state governments. However, the Fifth Amendment's due process guarantee, beginning with Bolling v. Sharpe (1954), has been interpreted as imposing some of the same restrictions on the federal government: "Though the Fifth Amendment does not contain an equal protection clause, as does the Fourteenth Amendment which applies only to the States, the concepts of equal protection and due process are not mutually exclusive." In Lawrence v. Texas (2003) the Supreme Court added: "Equality of treatment and the due process right to demand respect for conduct protected by the substantive guarantee of