Jonah Goldberg writes about patriotism and makes an effort to explain what Americans mean by the word. It is indeed a difficult thing to explain. If someone does not have any patriotic fervor then it is unlikely that they can understand why someone else does.
I believe that patriotism is the belief that America is fundamentally good; that it is the greatest nation so far created; that we are lucky to live in a nation of free people; that the pursuit of happiness is the greatest boon we can be granted.
That is not to say that there are no flaws with the U.S., but that we as a people work to repair those flaws. We disagree on what the flaws are, and on how to fix them, but we are able to do that in open debate, and to elect representatives who reflect our ideals and biases.
A measure of a nation's greatness is the immigration rate, and the emigration rate. People of the world are willing to endure hardships to get here, and, despite frequent comments about leaving the country if this or that happens, very few people elect to surrender their citizenship and move elsewhere.
I am proud to be an American, and know that no matter what the naysayers predict, the people of this country will not allow it to become a place of which they are not proud.