Sen. Hillary Clinton and Sen. Barack Obama are involved in a race for the Democratic presidential nomination that has already gone on longer than anyone expected. Now both camps are giving an idea of how that race will proceed. New campaign tactics are being hatched and tried out.
All along, Obama and Clinton have courted so-called superdelegates. These are party officials, Democratic members of Congress and other important figures whose votes at the convention are not determined by primary or caucus results.
Superdelegates can cast a vote for whomever they want. Since Clinton trails in the regular delegate count, the superdelegates are becoming especially important to her nomination prospects.
"People are superdelegates for a purpose," she told NBC News Wednesday. "They are to exercise independent judgment. And it's very important that they exercise that judgment based on what they believe will lead to the best nominee."
The Obama camp says superdelegates should not be permitted to overturn the wishes of Democrats across the country who participated in primaries and caucuses and gave Obama his current delegate lead.
Increasingly strong attacks on Obama by Clinton and her supporters represent a "scorched-earth policy" that are aimed at stopping superdelegates from endorsing Obama, his campaign says.
The Clinton campaign is warning that Obama is still a relative unknown, suggesting that some sort of damaging story could emerge before the general election.
Harold Ickes, a top Clinton adviser, spoke to reporters in a conference call Wednesday.
"I happen to be partisan in this," Ickes said. "We think Hillary has been vetted for the last 15 years. There's not another shoe in her closet to drop. It is clear that too much is yet unknown about Senator Obama."
Obama strategist David Axelrod offered a counter to that claim in his own conference call.
"Senator Clinton has a history of non-disclosure and even in this campaign she's been reluctant to disclose information," Axelrod said, citing Clinton's reticence to release tax returns or to name donors to the presidential library of her husband, former President Bill Clinton.
Obama also got in on the act. At a news conference aboard his campaign plane, as it sat on the tarmac in San Antonio, Texas, he challenged Clinton on multiple fronts — and pressed the media to go after her more aggressively.
"If the suggestion is somehow that on issues of ethics or disclosure or transparency that she has a better record than I have and is somehow better able to withstand Republican attacks — that's an issue that should be tested," Obama said. "So in the coming weeks we will join her in that argument."
Of course there are risks for each candidate if a prolonged period of attack and counter attack leads to the Pennsylvania primary in late April.
Obama risks tarnishing his image as a candidate who focuses on the positive and who pushes the need to change the tone in Washington.
Clinton, meanwhile, risks offending African Americans and younger voters whose support she would need in a general election contest against the presumptive Republican nominee, Sen. John McCain of Arizona.
One solution was hinted at by Clinton in a TV appearance Wednesday. She said she thought a compromise ticket featuring both rivals might be "where this is headed," adding that Ohio voters thought she ought to be the name on top.