That just shows exactly the mentality of the joke. It makes a certain type of person laugh because it is upsetting someone.
He defends it now by saying we should be more outraged about the government taking away the benefits of the disabled, therefore trying to turn it into a political statement.
I don't believe him. I think he was being a playground bully. And those laughing were the bullies sidekicks, who, as we all know, are far more pathetic than the people they are laughing at.