It's here, if you want to read it. And you should read it.
Patriotism is as necessary a part of man's evolutionary equipment as are his eyes, as useful to the race as eyes are to the individual. A man who is NOT patriotic is an evolutionary dead end. This is not sentiment but the hardest of logic.
Read it. It's a short speech as speeches go. But it's packed full of wisdom, as Heinlein is.