Please explain how the President is doing harm to the nation by urging prayer for the refugees.
I didn't assert Bush was harming the nation ---- I do not think the Constitution calls for the role of the President to be that of official State Muezzin.
Certainly plenty of American Presidents have called for national days of thanksgiving, prayer, etc. Other presidents have not. Jefferson resisted such acts, not because he didn't pray, but because he was President - not pope or preacher.