So Booker is less black than Obama?

[Vosem]

Interestingly, Barack Obama is actually slightly more than 50% African -- research has suggested that his mother is descended from at least one freed black slave in 1600s Virginia named John Punch.

On the other hand, because of the prevalence of the "one drop rule" in 1700s-1900s America, regarding people who were 1/4 black as being fully so was fairly common, and there are probably many African-Americans who indeed are mostly European in their ancestry, being only 25-50% African in their ancestry, but still identify largely with the African-American community. The roulette wheel that is genetics can sometimes give very extreme examples (like current NC Congressman G.K. Butterfield, who is black but appears hardly any darker than Hillary Clinton).

Basically anyone in America, of any race, can accept that regardless of the details of his genetic makeup Cory Booker is clearly black in a racial sense.