That was not a decision made by the president. A decision to fly flags at half staff for prominent residents of specific states is made by the governor of the state. The flags were half staff only in New Jersey for Whitney Houston's death, a decision made by Chris Christie. GOV. PERRY, of Texas did not make the decision to so honor Chris Kyle. You can read about this in Title 4 of the united States Code Chapter 1 Section 7 http://en.wikipedia.org/wiki/Title_4_of_the_United_States_Code
#TodayInCAHistory: On June 10, 1846, a herd of 170 horses en route to Alta California's acting Governor Jose Castro were taken by a group of U.S. settlers. Due to settlers' fears that the horses would be used by Castro to drive foreigners out of the Mexican territory, the herd was taken to the camp where U.S. Captain John Fremont and his troops were resting at the junction of the Bear and Feather rivers. The event was the first strike in the insurgency that became the Bear Flag Revolt.