1. The Obama White House is still in campaign mode. It only has approximately 12 months and 15 days to be in governing mode before the next presidential election campaign starts. You can win elections by hardening your base of support by attacking the base of your opposition. But it is extremely difficult, if not impossible, to govern that way. Attacks on Fox are, de facto, attacks on the people who watch it. Obama might need that base if he decides to accept the recommendation of his top general in Afghanistan and pour tens of thousands more American troops into that country — and his liberal anti-war wing turns on him. He may need Republican support to get a health care bill passed.
2. Attacking whole segments of the population belies Obama’s promise of bringing people together. Obama’s appearance on Fox commentator Bill O’Reilly’s show in September 2008 indicated a candidate’s willingness to be a different kind of president, to act on the stated desire of his predecessor, George W. Bush, to be a uniter not a divider. Obama got a fair shake in that interview.
3.There is still a thing called presidential decorum.