Voting Rights Act of 1965
Congress responded to rampant discrimination against racial minorities in public accommodations and government services by passing the Civil Rights Act of 1964. The Act included some voting rights protections; it required registrars to equally administer literacy tests in writing to each voter and to accept applications that contained minor errors, and it created a rebuttable presumption that persons with a sixth-grade education were sufficiently literate to vote. However, despite lobbying from civil rights leaders, the Act did not prohibit most forms of voting discrimination. President Lyndon B. Johnson recognized this, and shortly after the 1964 elections in which Democrats gained overwhelming majorities in both chambers of Congress, he privately instructed Attorney General Nicholas Katzenbach to draft "the goddamndest, toughest voting rights act that you can". However, Johnson did not publicly push for the legislation at the time; his advisers warned him of political costs for vigorously pursuing a voting rights bill so soon after Congress had passed the Civil Rights Act of 1964, and Johnson was concerned that championing voting rights would endanger his Great Society reforms by angering Southern Democrats in Congress.
Archibald Cox
The civil rights legislation that Kennedy was unable to see pass during his lifetime received the needed momentum from his death and the legislative skill of President Johnson. In 1964 the public accommodations bill passed as the Civil Rights Act of 1964. The obvious constitutional attack on the legislation was its constitutionality under the Fourteenth Amendment because it sought to regulate conduct that was not "state action." Cox and Assistant Attorney General and Head of the Civil Rights Division Burke Marshall, however founded the legislation on Congress's power to regulate interstate commerce. Although both John and Robert Kennedy questioned the optics of using the Commerce Clause, they did not object. Cox had no difficulty having the Court uphold the statute on that basis when he argued the cases in October.