Another slice off the top of my head.
Can one have both a national and an ethnic identity? Strange question in my opinion. From my point of view, this is like asking can a person own a bicycle and a car? They're both modes of transportation, but they are not mutually exclusive.
Let's make up an imaginary case. Well, partly imaginary. This individual is based on a dear friend who died some years ago. Was he American? You better believe it! I wonder if I need say any more than, he carried a badge. If there's any group that has a strong tendency to be firmly and devotedly patriotic, it's men in uniform, and this is even more true of those who carry a badge.
After all, these individuals are entrusted with the police power of the state. They are charged with representing the government in a one-to-one contact with a sometimes hostile public. If they don't regard themselves as thoroughly American, it's a surprise. In a very real and practical sense they are the government for most Americans.
Congress and the president are far away. We don't end up in court very often. And we only deal taxman once year, unless we've been naughty or careless. But unless we are stuck in the house all day, we are very likely to at least see one policeman drive by on a daily basis, which usually causes us to quickly buckle our seatbelt or get off the cell phone. Maybe both.
So there was no doubt that he was a loyal and patriotic American, which did not stop him from being a wild-hearted Irishman. Irish poetry or Irish whiskey, pretty much Irish anything, was part of his definition of himself. If you wore a kiss me I'm Irish button on St. Patrick's Day, he laughed and said, "Nah, you're not Irish. But I'll allow it, just for today."
He made it clear that he was very tolerant but that there was no race that could equal the Irish race. If you tried to call him on racial profiling he would only say, "Of course we're a separate race! Isn't that obvious?"
I don't think I have ever known anyone more American, and I'm absolutely sure I've never known anyone more Irish. Conflict? I never saw any.