[SlapHappyPappy]

For what it’s worth:

http://racerelations.about.com/b/2007/02/17/why-obama-wouldnt-be-the-first-president-with-african-ancestry.htm

[FredZarguna]

It's not worth anything. It's complete rubbish.

[heartwood]

Huh. That one-drop rule has gone positively homeopathic if those presidents have any black ancestry.