Consider statement #3 from the mission statement of the organization called the Gathering Of Eagles(Eagles). It calls war memorials "sacred ground" (http://gatheringofeagles.org/?page_id=83). The word "sacred" means holy. Its antonym is "secular" (meaning the here and now). This sentiment does not belong to these Eagles alone but to many who, without reflection, have put too much adoration on their country. Here, a distinction must be made between having a respectful love for one's country from deifying it.
Before answering that question, it might be useful to define religion first. Our first objective is to determine whether our religion is a human-initiated or a divine-initiated endeavor. In other words, when defining our religion, we need to ask if it was God or us who made the first move. If we made the first move in our religion, then that religion will meet some self-serving ends. For example, our religion might have been crafted in ways that provide us with a sense of belonging or a feeling of significance. Freud saw religion as a projection of the self. In either case, rejection of one's religion by an outsider will be taken personally.
The end result here is that it is logical for the patriot to go beyond dehumanizing to demonizing the critic become heretic. At this point, nothing the critic says can afford to be recognized. All must be burnt, hopefully metaphorically only, at the stake—including the heretic. This causes the saintly patriot to associate two seemingly opposite feelings. Those feelings are anger or even hate with the contentment or self-satisfaction that comes from a doing what is perceived as doing right—that is defending God. In essence, wrath is redemptive because it leads to peace.
Such a religion cannot be consistently held by the conservative Christian. We believe that our religion has been initiated by an all powerful God. We might get upset when people criticize our God; but because our God is infinite, God needs us to defend him as much as God needs a Starship--a notion that once confused Captain Kirk. If God is infinite, the best way to defend Him is to step out of the way.
Another test is how much credit do you give to your nation for what you have. To conservative Christians, God is the one who provides us with all things. Is that how you see your nation? Do you give your nation the credit for all that you have?
Another test of whether patriotism has become our religion can be seen in how far we will go to defend our nation's honor. Do we give ourselves permission to treat a critic of our nation in any way we please, even to demonize this person, simply because we claim to be defending the honor of our nation?
My guess is that far too many Americans have made patriotism their religion. This might explain why so many people react so vehemently to the criticisms from groups like the antiwar crowd. The criticisms that we have of America are all too obvious to the world and students of history. But these criticisms cause the American parishioner of nationalism to feel uncomfortable either about themselves or their future. This parishioner can then choose between lashing out in order to feel redeemed or worshiping another god.