It was a joke with transgenders being the punchline. No one has the power to force him to apologize or change his opinions. There just happens to be a whole lot of people who are trying to explain to him that what he said [b]is[/b] offensive to [b]a lot[/b] of people. If me personally said something offensive, even if I didn't realize at the time it was offensive and I didn't intend to offend people, I would unequivocally apologize for it. Because I personally think that would be the right thing to do.