The Canadian prime minister yesterday stated that they were widening the investigation of the leak stating that Obama had contacted the government to solace them on his NAFTA stance. The information that is already out suggests that Sen. Clinton accused Sen. Obama of doing exactly what she was doing. I think that the reason he hasn't come out on this is that he is waiting for the Canadians to come out with a report, and then the media to pick up on it.
"Prime Minister Stephen Harper promised Thursday that an internal investigation would probe all facets of how information was leaked that may have influenced the U.S. Democratic presidential primaries, including the alleged comments by his own chief of staff, Ian Brodie, and the subsequent leak of a sensitive memorandum."
"The controversy began after Mr. Brodie allegedly told a group of journalists from CTV News that candidate Hillary Clinton was not serious about earlier suggestions that she would reopen NAFTA if she became president. The network later reported that it was Mr. Obama's campaign that had informed Canadian diplomats not to be overly concerned that he would fundamentally change the deal. The network also reported that Ms. Clinton's officials indirectly tried to deliver the same message, a report the campaign denied the next evening."
http://www.theglobeandmail.com/servlet/story/RTGAM.20080306.wnafta07/BNStory/National/homeThe Clintons probably knew this could happen, but they did it anyway because they had to win Ohio.