At a time when election officials are struggling to convince more Americans to vote, advocates for the disabled say thousands of people with autism spectrum disorder, cerebral palsy and other intellectual or developmental disabilities have been systematically denied that basic right in the nation’s largest county. A Voting Rights Act complaint to be filed Thursday with the U.S. Justice Department goes to a politically delicate subject that states have grappled with over the years: Where is the line to disqualify someone from the voting booth because of a cognitive or developmental impairment? The complaint by the Disability and Abuse Project...