The summer of Minnesota’s discontent over voting rules has spun off a related fight: whether disabled people who cannot handle their own affairs should retain the right to vote. The debate has set off alarms among disabled people and their advocates, adding another layer of controversy to the legal and political battle over whether Minnesota needs a photo ID requirement for voters, changes in Election Day registration and a new provisional balloting system. “I want to vote,” said Dave McMahan, a 61-year-old military veteran with mental illness who lives in a Minneapolis group home and has his affairs controlled by a legal guardian. “I’ve been through sweat and blood to vote. I don’t want my rights taken away, because I fought for my rights here in the United States and expect to keep them that way.” Equally passionate is Ron Kaus of Duluth, an activist and plaintiff in a federal lawsuit that has raised the issue. Citing allegations in Crow Wing County in 2010, Kaus worries that disabled people have been hauled to the polls and told whom to vote for, which would be a crime. “It’s one of the sickest form of exploitation, political abuse,” he said.