It seemed that almost the day after JFK was assassinated, his programs fell apart; but not like you might think; they were put under new management and became vehicles for theft. The new management was in business to loot the government.
I don't think LBJ was aware of that, he didn't seem to be that kind of person, but anytime there are large amounts of money involved it requires close supervision.
No one can overestimate the importance of JFK in regard to the "New Frontier", and his killers knew that.