UPDATE - It looks like the "illegal political attack" has to do with a mailer implying that Sen. Baker received special treatment from UCA in return for funding. Here is the mail piece.
It really looks like White is reaching with this one. From what I understand, the "public property belonging to UCA" was a tent which Baker borrowed and later paid for. As for the "gifts and favors" that is so general it could be as minor as taking him to lunch and the "special treatment for his (son's) university housing" could be as little as getting him his first choice of dorm selection. White either needs to further explain these general charges with the details or apologize for this hit piece.
Also, Max Brantley adds to this on the Arkansas Times Blog. In defending White's mailpiece, Brantley points out that the mailpiece does not identify "Paid for by the Joe White for Senate Campaign" which Brantley speculates is why Sen. Bakers calls the ad illegal.