Perhaps- but if it happens after the convention then HHH becomes President, much like FDR/Truman in '44 IOTL. Also- LBJ forgets to reschedule RFK's speech. Since he's understandably in quite a mournful mood (nearly tearing up on stage, crying backstage in a stairwell afterwards) the delegates might, on the wave of emotion, follow him. After all- one of his personal and political traits was a sort of emotional communion. Closest parallel, though less genuine, would be Bill Clinton's "I feel your pain" charm of '92. He also sharply reminded everyone of his political emotions with "pay no worship to the garish sun." In Governator speak: "Ah'll be back, very, very soon."