I'd look at the way the wind was blowing internationally. Bush would be a moderate disaster if there was a quiet international scene (i.e. nothing on the scale of 9/11 or the clusterfucks he presided over) but an absolutely unfathomably bad disaster if there was a volatile world stage. Paul, on the other hand, would keep America out of any danger overseas (but probably to the point that the US becomes eclipsed) while wreaking horrific damage to the US domestically.
So I'll take the man who would be terrible, but might not be a complete disaster, over the man who would definitely be absolutely dreadful.