According to this:
http://ethnicelebs.com/cory-booker
Booker took a DNA test for the “Finding Your Roots” show, and the results showed:
47% African
45% European
7% Native American (higher than Elizabeth Warren )
It says that both his parents were black, and mentions only one white great-grandparent. But if he’s 45% European, then he must have more white ancestry than that, though where that comes from is not explained anywhere.
Has Obama taken one of these?
I know some blacks, including Jefferson's children, were three-quarters white. Jefferson's children, interestingly, were also his wife's half-nieces. I believe one of them had kids who were seven-eights white and whose descendants all married African-Americans. Being descended from someone born in 1860 who was seven-eighths white would make one pretty European.
On a similar note, North Africans, particularly Moroccans and Egyptians, have a surprising amount of ancient European ancestry. Mediterranean is often its own thing in genealogy test, as ancestry from Venice, Casablanca or Gibraltar, Istanbul, and Cairo all likely have a good amount of blood in common.
I think Jefferson's children were 7/8 white. If I remember correctly Sally Hemings was 1/4 black because her father was a white British man and her mother was a mulatto slave.