It follows from Trump derangement syndrome that has gone into remission. It's a feeling of over exuberance, and joy. Delusions of righteousness' and victory coupled with a forgetfulness of the crying , whining and gnashing of teeth one has done for the previous 4 years.
Usually grumpy Sally was passing out donuts this morning at the office, Bidenophoria does have its pluses.
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).