Schedule conflict, perhaps.
At least Michelle Obama wasn’t *quite* sleeveless.
Plane problems force Bill Clinton to miss Betty Ford’s funeral
http://www.latimes.com/media/photo/2007-04/29323346.jpg
Betty Ford | 1974
(White House / Associated Press)
President and Betty Ford look at a petition of “support and best wishes” signed by all 100 U.S. senators during her 1974 recovery from a mastectomy at Bethesda Naval Medical Center. At the time, breast cancer was a taboo subject, and she broke ground by not only disclosing her illness, but talking openly about it and her treatment.