On March 31, 1968, Lyndon Johnson announced he wouldn't run for re-election, due to McCarthy's primary challenge and the growing disillusionment with the Vietnam war (the Tet Offensive was two months earlier). He also announced he would seek to negotiate an end to the war, and supported Humphrey for the Democratic nomination.
Johnson's approval ratings in March 1968 were in the 60s (as far as Google will tell me...), while Bush's are in the 40s and falling.
So, I ask you, Dear Readers, what would it take for Bush to decide not to accept the party's nomination? (The GOP would then nominate someone in a floor fight in New York, presumably.)
