Nobody has produced any evidence that Perry is corrupt, unless taking donations is the definition of corruption.
Michele Bachmann has accused Perry of a quid pro quo without any evidence. That was a very slanderous statement regarding Perry and Merck, especially when she has no evidence of Perry or Merck breaking the law. However, what can't be denied is that Bachmann has taken thousands of dollars of donations from Merck's direct competitor, and continues to slander Merck.
Her taking money from GSK is no issue. Her taking money from GSK and publicly accusing its competitor of breaking the law and causing kids to be retarded is an issue. She was given just enough rope, and I will predict that her campaign will not recover from her false and asinine accusations.