This article is from the Conspiracy Theory Literature FAQ, by Xavier Poez firstname.lastname@example.org with numerous contributions by others.
A major CTL theme is that Lincoln and Kennedy were both on the verge
of introducing a currency that would be free of manipulation, control,
and profit by the world bankers, and were assassinated just prior to
implementing it. A speech that Kennedy gave at Columbia University
just prior to his assassination supposedly stated, "The high office of
the President has been used to foment a plot against the American
people. Before I leave office, I must inform the citizen of his
plight." [Andrews86]. See [Piper95], [Keith92] for information on the
One view is that the presidents may have been killed for multiple
reasons. A higher level conspirator (like a world banker, e.g.
Rothschilds [Perry94]) might have his own reasons, and convince a
lower-level conspirator (like an assassin or mobster) to kill Kennedy
for other reasons (such as hating his policies on crime, etc.)