Why Doesn't Obama acknowledge his White Heritage?

This is pretty strange. I guess that I don't understand why this is such a struggle. It also indicates to me a certain anger against whites that he won't even acknowledge his heritage. Is he worried that his black base will be upset if he acknowledges that he is half white? Why can't he even try bringing people together on this issue of race? Presumably it would be even more difficult for his children, though if a typical child were one-quarter asian or American Indian or I presume black, the child would be listed as having that racial background.

He may be the world's foremost mixed-race leader, but when it came to the official government head count, President Barack Obama gave only one answer to the question about his ethnic background: African-American.

The White House confirmed Friday that Obama did not check multiple boxes on his U.S. Census form, or choose the option that allows him to elaborate on his racial heritage. He ticked the box that says "Black, African Am., or Negro."

Obama filled out the form on Monday, supplying information for himself, first lady Michelle Obama and their daughters Malia and Sasha, as well as for Mrs. Obama's mother, Marian Robinson, who lives with the family in the White House.

For Obama, whose mother Ann Dunham, a white woman from Kansas, married his father, Kenyan native Barack Obama Sr., the question of his racial identity has been a lifelong struggle. His first memoir, "Dreams From My Father," is an account of a difficult journey of discovery. . . .