It's true, he can't.
You know why?
It's the sound-bite mentality most people have wrt politics nowadays.
Ron Paul isn't perfect by any means, but for the most part, he's right - even about 9/11. No, I'm not saying we're 'at fault', but the point is if we hadn't spent the previous century (+/-) screwing around with people's lives in the Middle East / Asia, we'd have a LOT less issues with al quada, et al. It seems that any time anyone says anything that in any way admits that the US's policies are anything but lily-white pure and good, they're called names. There's no intellectual discussion regarding the statements, it's a black and white world...
RP isn't blaming the US for 9/11 - the terrorists are solely to blame for such a despicable act - but he is pointing out that our often dastardly foreign policies have created a lot of ill will around the world and have drawn the ire of some truly horrible folks.
But of course all people hear is 'we're at fault for 9/11' and write him off, while the other dorks up there continue to repeat the idiotic mantra of 'they hate us for our freedom'. Neo-conservatism sucks.