b Roosevelt wanted to change the number of Supreme Court justices from 9 to 15 because he wanted to appoint 6 new justices who supported New Deal programs.
b. He wanted to appoint 6 new justices who supported New Deal programs.
Because he wanted to be able to pass his New Deal programs easier by appointing those who will support him, allowing him to continue with his agenda of helping the US out of the Great Depression.
