According to reincarnation beliefs, history tends to repeat itself until those who have participated in it learn their lessons and change for the better. This means that an individual may face identical situations from one life to the next until they are able to conquer whatever "cause and effect" chain-reaction they have caused from a previous life.
As an example, a person who "lives by the sword" in one life and dies without having made amends for his mistakes, will in the next life be faced with identical situations which must be overcome. Ultimately, such a person will have to face themselves and have inflicted upon them everything they have inflicted upon others. Divine justice in many religions shows that those who "live by the sword" will "die by the sword", if not in their present life, but likely in a future life. Reincarnation theory states that those who do not learn from history are doomed to repeat it.

The lives of President Kennedy and President Lincoln had so many parallels that it cannot be dismissed as pure coincidence. To my mind, these parallels are evidence of history repeating itself and evidence of reincarnation. To me, these parallels may be circumstantial evidence that President Kennedy was the reincarnation of President Lincoln. You decide for yourself.

Both were elected to Congress in ‘46.
Both were elected President in ‘60.
Both had the legality of their elections contested.
Both were directly involved with black civil rights.
Both lost a son while serving as President.
Both were killed while serving as President.
Lincoln was the first president to be born in the nineteenth century.
Kennedy was the first president to be born in the twentieth century.

Lincoln's staffer, whose name was Kennedy, advised him not to go to the theater.
Kennedy's secretary, whose name was Lincoln, advised him not to go to Dallas.
A week before Lincoln was shot, he visited Monroe, Maryland.
A week before Kennedy was shot, he was with Marilyn Monroe.
Both were shot on a Friday.
Both were shot in the head from behind.
Both were shot in the presence of their wives.
Both were shot while sitting with another couple.
Both were shot with another member of their entourage being injured, but not fatally.
Lincoln was shot in Ford's Theater.
Kennedy was shot in a Ford Lincoln.
Both assassins were born in ‘39.
Both favored extremist views.
Both are known by their first, middle and last names.
Booth ran from the theater and was captured in a warehouse.
Oswald ran from the warehouse and was captured in a theater.
Both were themselves assassinated before their trials.
Both President’s successors were Southern Democrats.
Both successors had the last name of Johnson.
Both successors were Vice-Presidents.
Both successors were born in ‘08.
Both successors were former senators.

The casket of both men was carried on the very same caisson.

It appears that history does indeed repeat itself. Perhaps it is the same cast of characters playing the same roles over and over again. Perhaps William Shakespeare said it best: