The Sunnis of Iraq are one th the three major factional groups, along with the Shiites, and the northern Kurds. It was predicted by many Iraq war nay-sayers that they would not buy in to participation in the new Iraqi political processes, since they are a numerical minority.
Guess again! They apparently looked around the station, realized the train was starting to pull out with or without them. Their conclusion was that they had better jump on board to avoid being left standing on the platform.