The U.S. Supreme Court ruled Tuesday that section 4 of the Voting Rights Act is unconstitutional because it relies on 40-year-old data that does not reflect racial progress and changes in U.S. society.

The court voted 5 to 4 to strike down section 4 of the act because it can’t be enforced until Congress comes up with a new way of determining which states and localities need closed federal monitoring of elections.

President Obama said the decision is a setback, but he is calling on Congress to pass legislation to ensure every American has equal access to the polls. The court did not strike down the part of the law that has been used to open up polling places to minority voters since it was first enacted in 1965.