527s are negative campaign orgs by definition. They cannot back a candidate but they san slam and tear down his opponent. 527s are not directly connected to the candidate in whose interest they campaign and spend money so they are freer to slime his opponent.
Politics was more honest when the DNC and RNC could get the big bucks soft money. They were accountable for any scurrilous TV advertising and other scurrilous campaigning. Now the soft money must go to the 527s.
And we can further thank McCain for going after the Swift Boat Vet's ad rather than attacking how his bill has been corrupted, mostly by the left. (I hate CFR but it just kills me that McCain has provided the most used comment on the Swift Boat Vet's ad.)