what does "myth" indicate here?
The ceremonies, conducted while the grieving republic mourned its fallen leaders, became folklore, and the very Bibles on which the new Chief Executives rested their hands were integrated into the myth. The Constitution, of course, mentions the Bible nowhere.
In time of crisis the pull of myth increases tenfold. On November 22, 1963, the typical American, like the typical correspondent in 101-102, was under the impression that the oath was mandatory.