From the Atlantic:
That's because, after a year of telling donors not to contribute to 527 groups, of encouraging strategists not to form them and of suggesting that outside messaging efforts would not be welcome in Obama's Democratic Party, Obama's strategists have changed their approach.
An Obama adviser privy to the campaign's internal thinking on the matter says that,with less than two months before the election and with the realization that Republicans have achieved financial parity with Democrats, they hope that Democratic allies -- what another campaign aide termed "the cavalry" -- will come to Obama's aid.
The Obama campaign can't ask donors to form outside groups; it can only communicate, through the public and the media, with body language, tells and hints.
The upshot: Obama's campaign will no longer object to independent efforts that hammer John McCain, just as, in their mind, the McCain campaign has not objected to those efforts targeted at Obama. "I assume with their 527s stirring, some [Democratic] ones will as well," another senior campaign official said.