I love hearing someone say "I disagree with what you say but I will defend to death your right to say it" because I have to question their commitment.
Are they really going to defend me when I say the most inflammatory thing I can possibly think of to the death?
Whose death, then? Mine, to shut me up before I say another inflammatory thing? Or are they going to die protecting me from someone else who doesn't like what I have to say?
If they are in the military I'll buy into their statement. Their duty is to protect the citizens and the Constitution. Otherwise, I'll just assume they are REALLY pissed off with what I'm saying and use the statement to calm themselves down like counting to ten.
That's when I shut up.