@Robert Gustafson,
Bob that's really a good q, as I've noted repeatedly that where it doesn't contribute to meaning, the comma is on its way out. However this time I tend to disagree with High, that it somehow provides a certain emphasis
Now, I feel like a criminal. Maybe, I ask myself, it depends on context. For instance, if the previous text has spoken of what many were supposed to think, then the comma might provide emphasis