A better excerpt would indicate that obama had referred to slaves as immigrants. At least I presume that is on the video in the article. (Can’t watch it.)
“Life in America was not always easy,” he said. “It wasn’t always easy for new immigrants. Certainly it wasn’t easy for those of African heritage who had not come here voluntarily and yet in their own way were immigrants themselves. There was discrimination and hardship and poverty. But, like you, they no doubt found inspiration in all those who had come before them. And they were able to muster faith that, here in America, they might build a better life and give their children something more.” ... President Barak Obama