While ACORN has long been are target of right-wing ire, McCain in true "maverick style" has lent his support to the organization.  It's funny that he is now so far behind in the polls he levels the ridiculous charge of rampant voter fraud on the part of ACORN.  Bertha Lewis, Chief Organizer of ACORN puts it best:

"It has deeply saddened us to see Senator McCain abandon his historic support for ACORN and our efforts to support the goals of low-income Americans. Maybe it is out of desperation that Senator McCain has forgotten that he was for ACORN before he was against ACORN; he was for immigration reform before he was against immigration reform; and he was a maverick before he became erratic. We were thrilled to partner with him to help reform the outdated immigration laws in this country, and were pleased to work closely with him on this issue."

It's funny that McCain is challenging Obama to be forthright about his relationship with ACORN and McCain has yet to be forthright about his past support for ACORN and his other contradictions that have defined his career as a public servant.  If you want more details about McCain's other contradictions in detail read Cliff Schecter's book The Real McCain.