Other than being old white guys with plenty of experience in the Senate, the two would appear to have little in common. Bernie will be relying on LBJ as a role model of sorts, however, because the Great Society is the best example of a major expansion of federal power that did not occur during an economic crisis.
Unfortunately, the analogy is unlikely to hold. LBJ was a very resourceful politician; JFK’s death created a degree of public sympathy for his agenda; and he ran against Goldwater. Bernie will have none of those advantages.