With Due Respect/Analysis

Why is it whenever someone says "with all due respect", they really mean "kiss my ass"?
Effectively, there are three explanations for this:


 * First, the phrase is being used ironically. They say "With Due Respect", but they don't mean it.


 * Second, it is being used as a half-hearted attempt to soften the blow, and hopefully avoid some of the retribution they would receive for just out-and-out insulting or contradicting someone in a situation where it would not be recommended to do so.


 * Third, they mean it literally, and are implying that there is no respect due to whoever they are addressing.