I'm still waiting for Obama to show us how he'll apply his gifts to these kinds of fights. In the meantime, he's smart to start with the conventional attack on Clinton's tax returns. Hillary's campaign has no substantive reason for not releasing the returns she's filed since she left the White House. They're presumably in a drawer in Chappaqua, N.Y., or in an accountant's office. It seems that she could present them in an afternoon if she wanted to.
The good news for Obama is that Clinton also may run into trouble if she looks too mean. It's not so much that primary voters in future contests might get turned off—they've proven to be pretty resilient this cycle. It's that Clinton's path to the nomination is highly volatile, and she'll only increase the chance for a political explosion if it looks like she won by playing ugly. Barring some extraordinary event, Clinton is not going to catch Obama in the race for pledged delegates. To win the nomination, she'll have to persuade superdelegates to upend the pledged-delegate totals. Her best chance at making this case may come if she wins the popular vote, at which point she could say that the people are with her. Absent that, she's going to have to argue that while Obama has the people and the pledged delegates, she's more electable because Obama is deeply flawed.
This is going to be a very delicate argument. According to the exit polls from Tuesday, two-thirds of Democratic voters said the superdelegates should vote based on the outcome in the caucuses and primaries, which means they should choose Obama. Clinton would be asking the party that thinks of itself as the protector of voting rights to unseat an African-American candidate who, if he stays ahead in the popular vote, has the voters' will behind him.
The strongest argument Clinton aides make on this score is that it's completely legal and fair for the superdelegates to choose whichever candidate they think is better. But legal and fair doesn't mean people will buy it. They'll be even less pleased if they think Clinton cheated or attacked Obama unfairly. According to those Tuesday exit polls, two-thirds of voters already do. That's why the Obama campaign will up the public umbrage they take at each little Clinton jab. Time to start sounding that alarm.