When they left Hawaii.. Obama was seen boarding the plane by himself.. and when he got to Chicago , he was seen getting off the plane without his family, even though his family was onboard.
He also was photographed in Hawaii going alone to see his grandmother (apparently, one visit) and doing a traditional lei ceremony without Michelle. The confirmation for me that something was amiss in the Obama household was when I saw Obama by himself at the 9/11 commemoration while John and Cindy McCain looked the traaditional presidential couple.