Why do you think discrimination still existed even after the passage of the Civil Rights Act?

Legislators cannot change minds and hearts, they can only create legislation that will ensure laws that provide fairness and equal protection to those who have been denied the rights that others naturally enjoy. If you review subsequent laws that followed the passage of the Civil Rights act of 1964, you will find many laws that slowly undid the voting rights act and Brown v. Board of education (1954). Politics has played a major role, along with lobbyists and corporations that stand to benefit from discriminatory laws and regulations and less oversight of areas where systemic and institutional racism persist such as housing, healthcare and education. Legislators henceforth do not work for John Q. Public anymore, they are corporate cronies.