“With all due respect” is the twenty-first century’s F-bomb. In the old days, when someone said with all due respect, it meant, “Yes, I hear you. Thank you for sharing your opinion. I appreciate the input, but I must respectfully disagree.” Today, it means, “Shut your big yap, because it’s my turn to talk.” Or, “With all due respect, that’s the stupidest thing I’ve ever heard.” Maybe even, “With all due respect, I wish you would drop dead.”
As far as I can tell, in 2008 no respect is due any more, and if someone with all due respects you, they are doing it with supreme irony and contempt. It’s a declaration of war. And with all due respect, I suggest you treat it as such.