Are We Exceptional?

Here's a story about comments made by Republican Representative Heather Wilson on the TV today:

"We are an exceptional country...We are a force for good. And we need to talk about the good things we do."

Is America truly "exceptional"?  What does this term even mean?  Is it inherently a good term?  How does one become "exceptional"?  Is an "exceptional" country allowed to act in any way that it pleases?  What are the good things that we are doing?

Is the labeling "exceptional" really just a way to say that we are better than everyone else?  Are we actually better than everyone else?  What are the metrics by which such things are determined?

What, in short, does this phrasing really mean?

It seems like the Republicans are throwing every turd they can at Obama in hopes that one will stick.