[rhysm]

Since the 8th seat raised and the 9th seat RERAISED, you may be able to expect a check from the 8th seat and a bet from the 9th seat on the flop, so you can raise and put the 8th seat to a 2 bet decision which may get you the chance to make him fold (if that's what you want). So, if you want to be able to protect your hand (which you should generally do at that level at Party :P), then the call on the pre-flop is a good idea to let you raise the 9th seat on the flop.
rhys