I have often used the expression "I could shoot myself" when I've screwed up. That does not mean I'm suicidal.
Epidemic joked (I hope) in the cats thread about shooting his cat. I don't think he's serious.
I don't think Mrs. Ehrlich has any intention of shooting Brittany Spears, and only a fool would think she was serious. It was clearly an expression of frustration.
Nor do I think Pat Robertson would really enjoy seeing the State Department nuked. Again, an expression of resignation and frustration.
Politicians have always used untrue expressions to create great speeches that motivate people and get a message across. Let's take some great speeches and re-write them so they speak only the truth.
"Ich bin ein Berliner." = "I'm a Bostoner who supports the people of Berlin." Hmm. Not quite the same impact.
"Mr. Gorbachev, tear down this wall." = "Mr. Gorbechev, hire some contractors to come out and dismantle this wall. And while you're at it, open your borders and let your people go." Well, maybe brevity is better with this one.
If we start picking apart every word uttered by every public figure, the art of fine speaking will fade away. Everyone will be so worried that the "speech police" will jump all over them that they won't say anything of substance at all.
Robertson and Ehrlich may both have used a poor choice of words, but what they said is hardly something to inspire the false outrage and indignation that everyone is screaming about.
EDIT: Oops. How'd I'd mess up her name so bad?

Thanks for subtly pointing that out,
Theo. Corrected.