I think it is the "Ma" bit that would be the really big issue, even for SM3. That said, look at its kinetic warhead's ability to manoeuvre above the atmosphere, so great without the "Ma".
However, when the target is a re-entry vehicle, it's likely to be going at a hell of a lick, and any manoeuvre is going to require a lot of turn by the interceptor and a lot of speed. It's one thing hitting a very high velocity ballistic target, quite another hitting a very high velocity MaRV.