Ford, Reagan, Bush I, Clinton, Gore, and now Obama and McCain are all left-handed. Call it chance or availability bias, but I’m still wondering. Read more here, and thanks to Martin Weil for the pointer. Here’s one on-line discussion. Here is a brief survey on Wikipedia. It is my general view that left-handers have higher genetic variance in a number of dimensions, so they should be over-represented in many different kinds of extreme situations, including the Presidency.