Jeremy asks: "Had Obama had to face a question from a MSM reporter about the pin recently before he decided to put one on?"
The short answer, of course, is no. Or at least a qualified no (see, e.g., the ABC debate question--which was delivered for reporters by a chosen proxy).
The longer answer is a bit more interesting. There has been, for some time, a subterranean (but frequently reported) campaign to raise questions about Obama's political and religious identity. This campaign has run from the original (false) "secret muslim" emails to the flag pin kerfuffle to the hand over heart kefuffle to Michelle's pride in her country to William Ayers to the current suggestion that Islam somehow requires Obama's murder. The drumbeat for this campaign emanates from the right, but (as many of the links above demonstrate) it has moved mainstream coverage and reached the point where some voters are openly echoing its premises.
“I heard that Obama is a Muslim and his wife’s an atheist,” said Mr Simpson, drawing on a cigarette outside the fire station in Williamson, a coalmining town of 3,400 people surrounded by lush wooded hillsides.
New York Times:
LATROBE, Pa. — Ask whom she might vote for in the coming presidential primary election and Nash McCabe, 52, seems almost relieved to be able to unpack the dossier she has been collecting in her head.
It is not about whom she likes, but more a bill of particulars about why she cannot vote for Senator Barack Obama of Illinois.
“How can I vote for a president who won’t wear a flag pin?” Mrs. McCabe, a recently unemployed clerk typist, said in a booth at the Valley Dairy luncheonette in this quiet, small city in western Pennsylvania.
Mr. Obama has said patriotism is about ideas, not flag pins.
“I watch him on TV,” Mrs. McCabe said. “I keep looking for that lapel pin.”
ABC later tracked down the same Nash McCabe to ask Obama a question about wearing the flag during the Philadelphia Debate.
Given that the Right's campaign does seem to be driving coverage and that voters (a least in Appalachia) have pretty much already moved to where the Right would like them to be in their perceptions of Obama, I think he had to start pushing back. And taking this one issue off the table, an issue that arises mainly from less than artful language and not any deeply held conviction, seems reasonable to me.