further left than V.I.U. wrote:
There were real reasons to be afraid. Mexican law enforcement made many student age protesters disappear. That was not a know fact by all fall, 1968, but there were rumors. That was a very violent time. M.L.K. had already been assassinated, spring, 1968. R.F.K. had already been assassinated, spring, 1968. Those were violent times.
Smith and Carlos knew about the Mexico City massacre of student protestors that had occurred right before the Olys. They were in communication w/ the students prior to arriving in Mexico City and their protest was explicitly for the slain, as well as for oppression in America. All this is detailed in John Carlos's autobiography and he will tell it to your face if you care to ask him.
That said, I doubt Smith fully expected to be killed on the medal stand.