If he eventually does decide to go after Obama he should be the last one on the list. Accumulate all the dirt from the others and squeeze them first. Then, if a case can be made on Obama go after him.
Don’t really need to.
In fact, given that he is the first Black president, it would IMMEDIATELY turn a legal issue into a racial one, and thus be VERY counterproductive for Trump and every Republican candidate.
Let “Slow Joe” and the party of “Lock Down” remain the major opponents for Trump to deal with, and leave 0bama out of the picture.
He would REALLY hate that!!