"Intervention under 24(a)(2) is MANDATORY, not discretionary."
Yes, but only if here is a statute that allows intervention. The AG relies on a statute that applies only if there is no representative of the state who is a party to the action--and Gore, for the purposes of issuing licenses is a state actor. Hence, the elements of mandatory intervention are not present. However, even when mandatory intervention is not appropriate, and as Peruta argues, the court in its discretion may nonetheless allow a new party to intervene, which in this case may have been more probable given the fact that Gore has stated that he will not further pursue the case.
Peruta's argument may be found here http://www.ca9.uscourts.gov/content/...id=0000000722: