The problem with saying Kennedy is better is the fact that he really wasn't in office for very long, especially in comparison to the time Obama has spent in office. I think Kennedy had some big legacies and he was very effective, but also much contested. I think Obama will surpass his legacy.
If you're more progressive/liberal, the answer is Obama. If you prefer the more conservative choice, Kennedy. Kennedy did next to nothing to help the middle class in his brief time in office and it was LBJ that led the crusade for poverty reform and civil rights legislation. Kennedy did help us get involved in Vietnam by setting things into motion, but Obama's god-awful drone strikes and continuations of the un-winnable wars in Iraq/Afghanistan pretty much cancel that out.
While president Kennedy was an able leader, Obama is a better president. President Kennedy was very much a friend to large corporations and Obama is changing that scenario. Obama has been a leader who is more likely to help people expand the opportunities they have available and profit in the future.
I do not think that Obama is a better president than Kennedy. Obama has not made that much of a difference since he was first elected in 2008. Kennedy was a president that inspired a nation and the people regardless of who they were. Obama is somebody that only works for the Democrats.
No, Obama is not a better president than Kennedy, because people on both sides of the isle liked Kennedy. He even almost had a celebrity about him. Obama is a divider. He calls people out that he doesn't like. He is even a little bit racist. I'd much prefer Kennedy again.