Let's look at context here: Why do you think it's being brought up, OVER and OVER and OVER again?
So that the name "Obama" can be equated with "terrorist."
That's the emotional connection being leveraged.
Do you REALLY not see that?
If that was NOT what the point was, then McCain would have stopped that attack long ago. He's trying to get the distaste and hatred for terrorists to rub off on Obama.
Big freaking deal if he's not calling Obama a terrorist literally, the impact is still the same... and he couldn't do that because obviously Obama is not a terrorist. Obama could disprove that. Here he can just make insinuations that Obama can't disprove.
So the point's not invalid at all. It's part of McCain's strategy.
And calling someone "computer illiterate" is not nearly anywhere near the same thing as saying they pal around with terrorists. Lord knows that McCain has had his own relationships with undesirables in the past, and dragging them out would be as lame as well.