It’s not that he had a criticism of Obama or Biden. It’s that he sent out a political message to “everyone on his email list” which included parents in his district.
Sending anything contreversial like that - and even such mild bashing will be seen as contreversial - to parents in a school district is a career limiting, or ending, move.
Think about it this way: If he had written a similarly benign ditty about there being no God...or pro-abortion...what would the reaction here be? Many here would be going over the top demanding he be fired.
It’s not about the content. It’s about the idea in general.
Think about it this way: If he had written a similarly benign ditty about W ... would he have been fired?
We both know the answer to that. It isn’t the goring of the OX, it’s whose Ox was gored.