Nate applied for a job as a business professor at CSUF

Nate applied for a job as a business professor at CSUF.  The dean decided that Nate 
was  the  best  applicant  for  the  job  and  offered  him  the  job  on  the  condition  that  he  pass  a  drug 
test.    Nate  took  the  drug  test  and  did  not  pass  (positive  for  marijuana,  cocaine  and  steroids),  so 
the dean withdrew the job offer.  Nate sued CSUF on the grounds that he was illegally required 
to  pass  a  drug  test.    How  should  the  court  rule?    Would  the  ruling  be  different  if  Nate  were 
required to take (and failed) the drug test after he had been teaching for three months?