Like Gore and Bush, these two political rivals took their intense hatred to new heights. Unlike Al & W, though, it ended up in murder.
Serving as Thomas Jefferson's vice-president, Aaron Burr was preparing his campaign for governor of New York, when his reputation was impugned in print by former secretary of the Treasury, Hamilton. The two had had a long-standing rivalry, and Burr challenged Hamilton to a duel. As that type of activity was illegal in New York, the two took a boat to New Jersey. At this point in American history, most duelers would simply fire their shots into the ground to signify their bravery and their mercy, but, firing first, Hamilton's shot went off wildly into the air (whether by accident or by design, no one can say). Burr, incensed, shot Hamilton square in the chest; Hamilton died from his wounds the next day. Charged by New Jersey and New York state with murder, Burr fled to South Carolina, before resuming his position of Vice President. Say what you will about Burr, but at least he's a better shot than some other veeps we've had, Dick Cheney.