An unnamed campaign adviser telegraphs a strategy to the Washington Post:
With Obama clearly favored in North Carolina, even he has called Indiana the "tiebreaker," a state that adjoins Illinois but where Clinton voters hold sway in the working-class towns in the south. In the two weeks leading up to the Indiana primary, a Democratic strategist familiar with the Obama campaign said aides are likely to turn to the controversies of Bill Clinton's White House years -- Hillary Clinton's trading cattle futures, Whitewater and possibly impeachment.
On a conference call this a.m., Obama manager David Plouffe flatly rejected the assertion. "We're not going to do that," he said.
There's certainly a balance to be struck between counterpunching and going negative. It's a hard line to walk because the media can't quite agree on what constitutes a legitimate response and what constitutes a negative attack. There is also some (healthy, vigorous) debate among Obama advisers about how to strike that balance. My sense is that Obama will reserve his harshest language for John McCain.