Make an Emotional Appeal
Connect your audience emotionally to the issue at hand. Appeal to their sense of compassion: Deliberately pull at the heartstrings. Start at a general enough point where the audience easily recognizes the common ground upon which you and they both stand. Emotionally invested, they will hear you out. For example:
As the video showed a man with violent tremors trying his hardest to speak with some fluency, I thought, "Can't we do any more for people like him?" The man I was watching had Parkinson's, a disease afflicting 1 in 5,000 people (Bennett, lecture). Due to the degeneration of that part of the brain that produces dopamine, a chemical that helps control motor coordination, patients afflicted with Parkinson's disease often suffer muscle rigidity, involuntary tremors and a shuffling gait.
I cannot imagine the frustration a person with Parkinson's disease must feel when tremors prevent them from holding a cup of tea. I cannot imagine the frustration they must feel when walking no longer comes with ease. I cannot imagine the frustration they must feel as they consciously know they are physically deteriorating. And I cannot imagine the frustration family members of Parkinson's patients must feel as they watch their loved one deteriorate and know that there is nothing they can do to help.
In answer to my own question, though, there is more we could be doing to help people with Parkinson's disease. Current research on fetal tissue transplantation shows great promise and could be a great benefit to many people. [The paper goes on to argue in favor of fetal tissue transplantation despite the controversy surrounding such a procedure.]