Behind closed doors, McCain is probably grateful for those tearing into Obama but he needs to keep them at arms length.
Here's a lesson in history for you. 2004. Bush hardly every criticized Kerry. He even dissed the Swifties. But the Swifties got their job done - with Bush donors' money.
You get it now?
Emasculating the guy pubicly with profuse regrets is more than keeping "arm's length".
It's how McCain always treats conservatives. Like red-headed stepchildren.