CORRUPTION'S SCENT: Sniffing feds make campaigns nervous.

Byline: Dave Davies

Nov. 27--AS THE 2007 mayoral election season begins and Philadelphia pols engage in the predictable frenzy of raising money, spreading rumors, begging and bluffing for support, talking trash and trading gossip, something is different from past campaign chatter: They're not sure who else may be listening. Over the past four years, the FBI and federal prosecutors have gone on an anti-corruption crusade, nailing more than two dozen people on corruption charges and shaking the city's Democratic power structure to its core. "I assume I have no confidential communications now. Everybody is mindful," said a politically active lawyer, who like many interviewed, spoke only on condition of anonymity.

Besides stirring uneasiness about who investigators are listening to, the probes and their legislative fallout have dramatically altered the rules for political fundraisers and donors. The combined effect is an …