Like the American flag that Francis Scott Key famously wrote about, the one on Barack Obama's lapel keeps appearing and disappearing.

The Democratic presidential hopeful said he generally stopped wearing a flag pin after the 2001 terrorist attacks because he felt it replaced "true patriotism" for some public officials.

Some Americans, however, say they question the patriotism of a candidate who makes such a choice, a sentiment that shows up in polls.

Last month, the pin briefly reappeared on his suit jacket. Obama said a veteran had given it to him that day and asked him to wear it.

It wasn't seen again until Monday, when Obama spoke to a veterans' group in West Virginia. On Tuesday, when he spoke about the economy to workers in Missouri, it was there again.

Asked by The Associated Press why he was sporting the pin again, Obama said, "I haven't been making such a big deal about it. Others have. Sometimes I wear it, sometimes I don't. We were talking with a group of veterans yesterday. Over the last several weeks people have been handing me flag pins. I thought it was appropriate" for what "we're talking about. I've just been leaving it on."

Asked if he probably will wear the pin from now on, Obama said, "Sometimes it ends up being on another suit. If it ends up being on another suit, I might leave it one day, but it's something that I've done before and I'll certainly wear it again."