In light of accusations from the Clinton campaign that there is still much unknown about Obama, Plouffe said, "If Sen. Clinton wants to have a conversation about electability and vetting, we're happy to have it. … The central assertions in her candidacy have proven to be false."
Assailing the Clintons' refusal so far to release any recent tax returns or the names of donors to the William J. Clinton Presidential Library, Plouffe asked, "What are the Clintons scared of? Why won't they release this information? … What's lurking there?"
Michael Elmore contributed to this report.