He is a very emotional man. He cares about America. He cares about the American dream. He cries when he thinks of how far he has come (never suspected he'd become one of the most powerful in America). And, he cries when he thinks that many of our children and grandchildren will never be able to obtain the American dream.
Keep in mind that the media is the one who harps on his crying. He probably doesn't do it that much (confirmed by his wife in interview), but THEY have to point it out every time they talk about him - that and his tan and his golfing and his drinking and, well, you know how the media is?
I like the guy, so I will ignore the liberal media and other snide comments.