She did this during the Benghazi hearing after hours in front of the committee. A sign of aging and fatigue: The epiglottis fails to cover the windpipe opening quickly or completely enough when swallowing, and coughing ensues. Hillary is not physically or mentally fit to be POTUS, let alone her Stalinist views on just about everything.
Probably, but I get coughing fits from sinus post-nasal drip often. The snot hits that spot and you have to cough.