If there is one thing I'd expect an American politician to be good at it is coming across well on TV. It is a pretty basic competence and their politics is supposed to be more professional. However, I can't imagine any British politician being this bad:
There are two options on TV:
1) Stare down the camera. This is generally done when you're being interviewed remotely - "from our Westminster studio" - and you must on no account ever look away. If you look away even for an instant then you look shifty.
It's difficult. The questions will often be coming to you from a speaker to the side and the temptation to look at your questioner is a powerful natural reflex you've got to completely kill.
2) Look at whoever you're speaking to. Let the camera be a fly on the wall watching you give a speech to ordinary people. Don't look down the camera or you'll break the illusion of reality.
Either option works, neither is 'right', but you can't fudge the issue. The half way house McCain occupies in this speech makes him look shifty, nervous and amateurish.