Oh please. Stray bullets are pretty rare, especially around a president.
The Warren Reports suggests magic bullets are much more likely.
Stray ones, yes. Intentional ones, not as rare as we'd like. Lincoln, Garfield, McKinley, and of course Kennedy were all assassinated by via gunshots. Attempted assassinations by gunfire include Jackson (guns misfired),T. Roosevelt was shot while running for a third (non continuous) term as a "Bull Moose", Truman was shot at, sort of, by two Puerto Rican "nationalists", (the surviving one was pardoned by J. Carter), two attempts were made to shoot Ford, although a shot was only fired in one of them, and of course Ronald Reagan was also shot.
I'm sure there are plenty of both "free lance" and "organized" Jihadies that would like to have a go at President Bush.