Somoza was diagnosed with cerebral palsy and spastic quadriplegia when she was born and uses a wheelchair. She responded to Donald Trump's apparent mocking of a New York Times reporter in November 2015.
"I fear the day we elect a president who defines being an American in the narrowest possible of terms, who shouts, bullies and profits off of the vulnerable Americans," she said.
"Donald Trump has shown us who he really he is. I honestly feel bad for anyone with that much hate in their heart."
Somoza has been an advocate for people with disabilities since the 1990s. She appeared at a town hall meeting for kids in 1993 and asked President Bill Clinton a question.
She interned for Hillary Clinton in her U.S. Senate office and previously worked on Clinton's 2000 campaign for Senate.
"Over the past 23 years, she has continued to serve as a friend and mentor, championing my inclusion and access to classrooms, higher eduction and the workforce," she said.
"She has never lost touch with people like me. She has invested in me. She believes in me. And in a country where 56 million Americans with disabilities so often fill invisible, Hillary Clinton sees me."
Somoza continued to slam the Republican presidential nominee, saying he doesn't represent her.
"Donald Trump doesn't see me, he doesn't hear me, and he definitely doesn't speak for me," she said.
In an interview with CNN's Don Lemon, Somoza said she was "personally offended" by Trump mocking the appearance of the reporter with a physical disability and felt she had to speak out.
"Anyone who doesn't agree with him is stupid or wrong," she said. "That's not who we are in America."
In a Facebook Live, Somoza added why she could not support Trump.
"He's literally insulted almost every group, every person that makes up the fabric of our country," she said. "It's a campaign that feeds off of fear and division."