Misunderstanding of Delayed Results
Sometimes, we look at a situation and blame the leader, when the situation is the result of factors which took place in the past. Causes can have delayed effects, and just because Person X was in charge when Effect Y happened, doesn’t mean that Effect Y is because of decisions made by Person X. Effect Y might ultimately have been caused by what Person A did 100 years ago.
See also The U.S. Economy is Complex and Slow-Moving