President Obama's Half-Brother Pens Revealing Book About Growing Up Obama

INSIDE EDITION spoke with President Obama's half-brother, Mark, about his new book and their relationship.

When President Obama spoke out about the horrifying Ray Rice elevator attack he said no man who hits a woman is "A real man."     

Now, the president's half-brother, Mark, says there was a very personal reason why the president condemned Rice.

Mark told INSIDE EDITION, “He said any man or a real man does not hit a woman and this was the first time I have ever seen my brother say something so powerful and so direct to the issue of domestic violence and it made me very, very proud.”

See More of Mark's Interview with INSIDE EDITION

Mark Obama and the president have different mothers but the same father—Barack Obama, Senior.

In Mark's new book, An Obama's Journey, he paints a disturbing portrait of their dad as an abusive, violent alcoholic.

“It was the absence of a father that affected him. In my case, it was the presence of a father,” said Mark.

Despite his praise for the president, Mark acknowledges there's a rift between them. He writes that his first impression when he met the president back in 1988 in Kenya was that his half-brother was "a stuck up [expletive].”

INSIDE EDITION’s Les Trent said, “You guys didn't really like each other.”

“This is what I felt at the time,” answered Mark.

When Mark turned up unexpectedly at a campaign stop back in 2008, it was one of their few meetings and the reunion looked awkward.

Today, the president is beset by crises and plummeting poll numbers, but Mark says he'll always be proud of his brother.

He said, “He's my brother. We’re family.”