There are roughly 222 million Americans old enough to have gone to Harvard. Of these, only 279,000 have actually attended Harvard. If we crudely assume that Harvard is the pinnacle of credentials, attending Harvard puts you at the top one in 796 level achievement (normalized Z score = +3).
Meanwhile of America’s 76 million baby boomers (alive or dead), only four grew up to be President of the United States (so far). If we crudely assume being President is the pinnacle of power, the Presidency puts you at the top one in 19 million level. The median U.S. president would therefore be at the one in 38 million level in power (normalized Z = +5.47).
Of the five living U.S. President, two have attended Harvard (Bush & Obama), so an achievement that is +3 Z in the general population, is only +0.27 Z among Presidents. This implies the average U.S. President is +2.73 Z in education (3 – 0.27). Considering the average U.S. president has an IQ of about 130 (+ 2 Z), this implies education is more important for achieving power than IQ (as Lion of the Blogosphere would agree).
This makes sense because education reflects not just IQ but social class and work ethic as well.
We can estimate that IQ correlates 0.37 with power (2/5.47) while education correlates 0.5 (2.73/5.47).