IF my employer has a campus in 2 states and I work in both states, CAN both states tax me on a 401K withdrawl from a previous employer OR can only my home state tax me?

I think the answer is more of a "maybe" than a "no."  But you need to review the requirements for reporting income by the non-resident state.

In general, income you receive while living or working in state #2 can be taxed by state #2, while all your world-wide income is taxed in your home state.  If the 401k withdrawal was made while you were physically living on working in state #2, state #2 might want to try and tax it.  It depends on the laws of state #2.  (If the withdrawal occurred while you were physically living or working in your home state, it is definitely not taxable by state #2.)

Timing may also matter.  It may make a difference if you were in state #2 for two weeks or 9 months, for example.  You need to look at the laws for state #2. 

As @DoninGA stated, a distribution from a 401K is taxable only by your state of residence at the time you receive the distribution.  The state in which the 401K contributions were made is irrelevant.