GREEN BAY, Wis. – More often than not, when Senator John McCain wraps up a rally or a political event, he will close by telling the audience about Matthew Stanley, a young man from New Hampshire who was killed in Iraq in December, 2006, whose name is on a black bracelet Mr. McCain has worn since Mr. Stanley’s mother gave it to him.

But when he wrapped up a big rally with Gov. Sarah Palin at a hockey arena here Thursday night, Mr. McCain closed with a stunning new line.

“Every once in a while you have an experience that’s very helpful to put into the right priority what this campaign is all about,’’ he began, in much the same way he usually begins the Matthew Stanley story. “And that just happened to me a few hours ago.’’

Mr. McCain said that a woman had greeted him at the airport in Wisconsin and handed him an envelope.

“Then I got back on the bus and I saw this envelope, and the envelope was from Cheryl Lee Patrick from Ladysmith, Wis.,’’ he said. “And on the front of the envelope it says: ‘To Senator John McCain. My son, Staff Sgt. Patrick Lee Lybert, K.I.A. June 21, 2006, Afghanistan. And then the note goes on to say: please remember and support our troops in Afghanistan. God bless you, Cheryl Patrick.”

“And then I opened up the envelope,’’ Mr. McCain said, doing so on stage as a clinking sound was heard over the sound system, with many in the audience of the arena gasping audibly, “and there was the dog tags.’’