WHEN BIG BUSINESS AND SPECIAL INTERESTS try to sway political candidates with the offer of campaign "contributions," rarely is the deed done so baldly and so publicly. Usually it's done behind closed doors, between intermediaries to buffer the transaction from prying eyes. But mayoral candidate Michael Nutter is not just any candidate. When the "special interest" in the black hat tried to "pay to play" Nutter turned him down cold in front of witnesses at Dirty Frank's bar. No sir, it will take more that a twenty dollar bribe to crack the wall of integrity that is the Nutter candidacy.