> I wonder if there is any negative effects associated with being refused entry by a CBP? Could it be the case that if you are refused entry once, that in the future they will be more likely to refuse you entry? If so, that's a fairly significant penalty/power that the CBP person has.

Yes, some categories of non-citizen visitors (I don't remember which) are asked on the form if they have ever been refused entry to the U.S. (and are required to answer yes or no). If they're using the same passport number as before, CBP likely also has access to a computerized record of the previous interaction.