New York - MSNBC's Chris Matthews says President Barack Obama has done so much to heal racial divisions that Matthews "forgot he was black" while watching his State of the Union address.

Those four words - "forgot he was black" - so instantly set the Twitter world afire that Matthews came back less than 90 minutes later Wednesday night to explain what he meant.

The MSNBC commentator said it was noteworthy to him that a black president was addressing a room of mostly white people and how it didn't seem to be an issue. He said he saw it in the context of growing up at a time racial divisions were ever-present.

Says Matthews: "I went in the room tonight, you could feel it wasn't there tonight and that takes leadership on his part, to get us beyond those divisions."

- Associated Press