The ideas behind libel and slander laws apply here. The larger your public profile, the less protection you have from libel and slander.
Mr. Romney was saying politically relevant things at a politically relevant dinner while running for a political office. The recording was perfectly legal and I'd consider moral. The people have the right to know the truth about the politicians they're voting on.
I don't pay much attention to American politics, but Romney was running for public office. Arguably the most powerful political role in the world, which makes his private opinions very relevant to everyone.
If you run for public office and believe that everyone who [correction: doesn't] vote for you is sub-human, that is a reliable indicator of how you will treat the people who didn't vote for you.
What are your thoughts on the Romney 47% remark? (that was recorded by a bartender at the event)