I cannot hold down a debate, at least in the face-to-face format, because I become either a foaming angry mess or a quietly mumbling nothing. Usually I need time to form my thoughts. That doesn't mean I'm not fantastic at gently getting around or redirecting or deflecting debates when there is a need to do so, but actually joining in, fighting the fight, advancing a cause through brute on-the-spot logical and rhetorical manipulation? Nope, not in most cases. Likely, for most who have AS or autism or whatever, we need or like to know A LOT about what we're saying before being prepared to wade in on a subject, and even then we may get lost in minutiae, because that's how we are. Written communication is different, as several people noted already...
These are my thoughts. I have often tried to break through that wall of being poor at debates, with what I perceive to be poor results.
All that said, at least some people whom I consider to have stellar debating skills have said I'm good at it, or good at holding logical conversations, or something good that doesn't make me sound like an abject failure in the field of talking with less than complete agreement with other people, so perhaps this is in my head and owing to some overly high standards that ought to be shed. Who knows. But there does seem to be a pattern here.