Harkin agreed. “Never has the issue of disability rights and inclusion been this prominent in a national convention,” he told TIME.The connections were often personal. Somoza worked on Clinton’s 2000 Senate campaign and interned in her Senate office. Moore, 29, met Clinton when he was 7 years old at a health care event and kept in touch over the years. And Haubert spoke about Clinton’s work with disabled children at the Children’s Defense Fund.But there was a political reason for the focus on disability rights as well.

“Donald Trump has shown us who he really is and I honestly feel bad for anyone with that much hate in their heart,” Somoza told the crowd. “Donald Trump doesn’t see me, he doesn’t hear me and he definitely doesn’t speak for me.”

In June, a super PAC backing Clinton launched a $20 million ad campaign in seven swing states highlighting the remarks and featuring a response from parents of a girl born with a spinal birth defect. A strategist for Priorities USA told the Wall Street Journal the mocking showed “proof that he lacks the character” to be President.

Disability rights advocates understand the politics at work. “Donald Trump mocking the reporter from the New York Times is something the Clinton campaign has decided is an important issue for them,” said Andy Imparato, executive director of the Association of University Centers on Disabilities. “Having people with disabilities take on Trump is an effective strategy for Secretary Clinton. But I’m hoping that it’s more than that.”

Imparato, who worked for Harkin in the Senate, said the Democratic convention will be the moment people saw Americans with disabilities become a major political force in the party. Before this week, “my feeling is we were invisible,” Imparato said. “There are things happening this week that I’ve never seen in the time I’ve been doing this work.”