After having beaten Hillary Clinton in twelve consecutive contests, Barack Obama's losses in Ohio and Texas have halted his momentum, and have dealt a blow to his own aura of inevitability. As many observers have noted, last night's losses pushed the "re-set" button on the presidential race. Both campaigns must now start rethinking their endgame. This is especially true for Barack Obama.

On January 21, on the eve of the South Carolina debate, I urged Obama to respond forcefully to the Clinton campaign's charges that he had flip-flopped on the Iraq war, and that he had supported the views of Ronald Reagan. No presidential contender, I warned, could let such charges stand without losing the respect of the voters. To his great credit, Obama was thinking along the same lines that night, and confronted Hillary fiercely in that South Carolina debate. While pundits expressed horror at the contentiousness of the debate, I still maintain that the spat was transformational for the Obama campaign. The electorate at large, and Obama's African-American base in particular, needed to see that Obama could be a fighter.

Such confrontation however, does not come naturally to Obama. To be sure, his charm, warmth, and equanimity have put him in good stead in the presidential race. His personality has been essential in reassuring a predominantly white electorate that is always skittish about the prospect of an "angry black man." Obama has shown that he is capable of being a president for all the people.

The problem is, there is a flip side to Obama's vaunted cool and ease: He is somewhat conflict-averse. The same attributes that make him successful in one situation, can become a hindrance, crutch, a cop-out in other situations. There are times when Obama needs to confront, engage, and even attack, when he merely takes refuge in placidity. In the latter stages of the battle for Texas and Ohio, Obama was not only out hustled by Hillary Clinton, more importantly, he was out toughed by her. In the final days, he stood by and caught charge after charge, without adequate response.

Obama has relied so heavily on his charm and unflappability, that he has come to rely excessively on these qualities. When your opponent says, "With respect to answering the red phone at 3 in the morning, I have experience, Senator McCain has experience, and Senator Obama has a speech that he gave," you need to respond clearly and forcefully. Obama did not. Obama's disappointing showing in Ohio and Texas in part stemmed from Hillary's ability to cast herself effectively in the role of "Commander in Chief," while Obama was put in the role of the naive boy scout. Let me be blunt about it: By adopting a soft prevent defense in the face of withering criticisms from Hillary, by refusing to play any offense, by not punching back effectively, Obama has been placed in the position of--dare I say it?--a sissy. That is no way to win the support of a trucker in Akron, or a bricklayer in Sandusky.

And while Obama, perhaps armed with a false sense of security, had settled into a passive role, Hillary, with her back against the wall, has had both guns blazing. The amazing, even shocking support given Hillary by "Saturday Night Live" cannot be underestimated. Hosting the show, SNL alumna Tina Fey, did Hillary a world of good, by bringing to the surface Hillary's dirty little secret-- the fact that people view her as unacceptable because she's perceived as a bitch. Said Fey:

Maybe what bothers me the most, is that people say that Hillary's a bitch. Let me say something about that: She is. So am I. And so is this one [pointing at Amy Poehler]. You know what? Bitches get stuff done!

When Fey uttered those words, I imagined millions of women around the country--all of whom have felt the sting of being put down as "too pushy"-- jumping to their feet and cheering. The SNL skits were a major boon for Hillary, for three reasons: First, they gave a patina of "hipness" to Hillary, not often thought of as young or hip; second, they lampooned Obama as a goofy, grinning pet of the media; third, they made a virtue of something that was formerly taboo, being in touch with your "inner bitch." Clinton benefited from each.

So what should Obama do? Simply put, he should tap into his own wellspring of anger and indignation. When you are trying to establish a new, affirmative, principled politics, there are two ways that you can go about it: 1) You can simply refrain from attacking your opponent, a tack which is ultimately foolish and self-defeating. 2) Or you can hit back at an unprincipled opponent, as long as your criticisms are sincere, accurate and conscientious. For example, I heard Obama on CNN this morning answering a question about "the red phone at three in the morning." Obama responded that if it were a matter of one's resume rather than one's judgment, "then John McCain should be answering the phone." This is at best a weak reply. What he should have said is this:

Hillary still doesn't get it. If all we're doing is looking at resumes, why don't we nominate Dick Cheney? He's got more experience handling crises than anyone. Or how about Don Rumsfeld? Who has more experience than him? Her ad completely misunderstands what it takes to be president. Besides, even using her own criteria, Hillary fails the test. She has no such foreign policy experience, short of serving tea to foreign potentates!

One of Clinton's standard campaign gambits is to refuse to say whether she thinks Obama is qualified to lead the nation, implying that she secretly thinks he isn't, but is too nice and diplomatic to say so. Such statements should elicit sharp, consistent attacks from Obama:

Nobody with any intelligence and competence who serves with me in the Senate has the slightest doubt about my capabilities as a president: Chris Dodd, 27 years in the Senate, Ted Kennedy 46 years in the Senate, Jay Rockefeller, 24 years in the Senate, have all worked extensively with both Hillary and me. And you know what? They've each endorsed me. The message here is obvious: The odd person out here is Hillary; the fact that she can't acknowledge my qualifications is a tired campaign ploy, and tells you a lot more about her, than it does about me.

The tactical principle is very simple: Every time that Clinton practices the old politics of character assassination, Obama should make her pay a price. He should call her on it relentlessly. Take, for example, this gem from Hillary: "Barack Obama thinks that only your children should have health insurance."

Obama should hit back in this manner:

Beware of politicians who will say anything to get elected. Hillary knows full well that my health insurance plan is portable, cost-controlled, and available to any American who wants it. This is yet another distortion, another example of the old politics.

Or how about the consistent claim that Hillary makes, that she "won" Michigan and Florida?

You know, it takes a special kind of gumption to sign a pledge that the Michigan primary wouldn't count, watch your opponents all withdraw their names from the ballot, and then claim victory for yourself. The claim is no less ridiculous and unprincipled now than it was a month ago. As for Florida, in any state in where there is no campaigning, Hillary would win by virtue of simple name recognition. Had there been no campaigning in Virginia and Maryland, she would have won those states too. After we did campaign, Hillary lost them both big time. Given that, those Florida results mean nothing.

The controlling idea behind Obama's endgame should be that of unmasking Hillary's misrepresentations. A candidate who doesn't play straight with the electorate creates numerous vulnerabilities for herself, numerous points of attack. Obama's responsbility to his own campaign is to highlight those vulnerabilities. Hillary has found her "inner bitch." Obama needs to find his own.