I always figured that an activist judge was one who came up with decisions that you don't agree with. As far as textualism goes, the opinion of Justice O'Connor on the use of a firearm to obtain drugs was a particularly egregious example. And, as I remember from the Nunberg piece, textualism was explicitly defined as not paying any attention to the intent of the law-makers. I remember reading a Louisiana anti-abortion statute that could, in the hands of a clever word-slinger, be interpreted to outlaw caesereans.