The Americans with Disabilities Act claims that "The continuing existence of unfair and unnecessary discrimination and prejudice denies people with disabilities the opportunity to compete on an equal basis."
Why do the authors include Part 4 in this section? How is Part 4 related to the claim? (4) Census data, national polls, and other studies have documented that people with disabilities, as a group, occupy an inferior status in our society, and are severely disadvantaged socially, vocationally, economically, and educationally.

Question

The Americans with Disabilities Act claims that "The continuing existence of unfair and unnecessary discrimination and prejudice denies people with disabilities the opportunity to compete on an equal basis." 
Why do the authors include Part 4 in this section? How is Part 4 related to the claim? (4) Census data, national polls, and other studies have documented that people with disabilities, as a group, occupy an inferior status in our society, and are severely disadvantaged socially, vocationally, economically, and educationally.