As has probably been discussed before, Arthur Bremer, the man who would later shoot and paralyze Alabama Governor George Wallace, had initially plotted to kill then-President Richard Nixon. On April 13, 1972, Bremer traveled to Ottawa, Wisconsin with a revolver tucked into his jacket pocket, intending to shoot and kill the President during a campaign event. However, put off by tight security and feeling he had no real opportunity, he returned home to Milwaukee.
But what if Bremer had found the golden opportunity he hoped for, and shot President Nixon, killing him? Vice President Spiro Agnew would evidently become President, but would he be made the head of the Republican ticket for the upcoming election? IOTL, Nixon apparently considered replacing him heading into the '72 cycle; would he have any shot at becoming the Presidential candidate? Assuming he did, two other questions come to mind: 1) Who would have been chosen as his running mate? and 2) How would he do in the general election? Would he win off of sympathy for the fallen President alone? And of course, the biggest question here might just be, how does this impact Watergate (assuming it still becomes public)?