I would guess this is hurting McCain. And prior to Bush's endorsement:
"So, anyway," Bush said to the reporters who had assembled there to see the two men shake hands. "As I was saying . . ." He smiled a bit, but no McCain. He did a mock soft-shoe dance. "I'm just going to tap-dance a little," the leader of the free world said. Finally, he disappeared into the White House, telling onlookers: "Pretend like it never happened."
You can just watch the video: