Complex sentence: He also pushed through the Voting Rights Act of 1965, which set strict rules for protecting the right of African Americans to vote--that have since been used to enforce equal rights for women as well as all minorities.
Split into simpler sentences: He also pushed through the Voting Rights Act of 1965, which set strict rules for protecting the right of African Americans to vote. This law has since been used to protect equal rights for women as well as all minorities.