Patriotism in the US can definitely be too jingoistic. If we start to feel we are better than everyone else and shouldn't take anything from anyone this can happen. I don't think we are at that point right now. I think there are enough people who feel we should stay out of foreign affairs.
Unfortunately, patriotism in the United States often becomes jingoism. The fact of the matter is that Americans think they are better than other countries. Such a jingoist attitude has been prevalent since the country fought for and won its independence. These attitudes won't disappear any time soon as far as patriotism is concerned.
From what I have seen, many people use it to profit. From,what I have seen, many people use it to put down people with differing points of view. Many of these people never even served in the military. Many of these people let our veterans go homeless and then say things like, "let the homeless rot." How patriotic is that? Then, they will go on for days about America this and America that.
Jingoism is the feelings and beliefs of people who think that their country is always right and who are in favor of aggressive acts against other countries. I do not believe patriotism in the United States takes this form, especially not currently. Pre-9/11 I believe we displayed these tendencies often and I believe it won us enemies.
Patriotism for one's country is never a bad thing and there really can't be too much of it. If the leaders of a country commit some horrific act via their power of authority, it's the leaders that have done this, not the people of the country. This seems to be a widespread problem of failing to recognize that the acts of leaders are not the acts of the millions (or billions) of citizens within that country. The people of China and Iran are generally decent people but, unfortunately, they get judged by the actions of their leaders. Most people in the USA are very patriotic however, political correctness has plagued this country to the point where people feel that a moderate amount of patriotism is extreme. To say that one can be too patriotic of their country is something that only an apologist could render. They are afraid and they are weak. A free country cannot stand in the face of adversity with this mindset. I say get rid of the failing leaders and authorities, and go USA!