This sense of rhetorical occasion, what the Greeks called kairos, has a particular role in presidential oratory that is aimed at times of disaster.  Elements of oratory from World War Two statesmen like Franklin Delano Roosevelt and Winston Churchill play a role in these speeches.  Bush also uses Clintonesque empathizing at times of national grief. complete with the personalizing touch of mentions of particular proper names of victims.

The place is also important: the Oval Office, the South Lawn, the National Cathedral, the chambers of Congress.  Each location orients Bush's rhetoric for televised presentation either with or without the punctuation provided by audience reaction.