Mitt Romney’s political and ideological squishiness has been examined since he first started running for president more than five years ago. Often, the certitude and principled hard-headedness of his father, George Romney, the governor of Michigan and himself a presidential candidate, is conjured to make a stark contrast between father and son. George Romney storming out of the 1964 Republican National Convention has become a central detail to draw the comparison, and a founding block of the Romney creation story.

Except that it appears to be nothing more than a myth.