“We are too infrequently a part of the conversation,” said Lex Frieden, one of the chief architects of the 1990 Americans With Disabilities Act. Summit organizers ultimately invited Frieden to speak on a panel about social justice. But disability rights supporters say the episode was a wake-up call to mobilize in bigger numbers and stop being an afterthought. Advocates have launched a voter registration and education effort. They’re inviting candidates for top political offices to speak at a September conference on disability issues. They’re planning events to celebrate the upcoming 25th anniversary of the Americans with Disabilities Act. “Disability rights are civil rights,” said Bob Kafka of the advocacy group ADAPT of Texas