Playing an aggressor on the bubble

[wulfheir]

How do you play against an aggressor on the bubble? I've only recently become comfortable pushing the table 4 or 5 handed, not afraid to put my chips in the middle to pick up those blinds and limpers. But when I run into another aggressor who's doing the same thing, I don't really know how to deal with him.

My calling range against him tightens right up, including only mid PP and better. But if he's been tight early in the SnG and aggressive late in it, I can only assume he's playing a wider range of hands, yet I'm narrowing my calling range because I'm scared of him. Should I just let him do his thing while I do mine? Or should I be looking to push up against him?