Why did Obama let Clinton jerk him around over Samantha Power?

Here's the revolting and ridiculous conference call, in which Clinton campaign hacks pretend it's a giant outrage that the brilliant Samantha Power applied the word "monster" to Hillary Clinton. Power withdrew herself from the campaign, but where was Barack Obama? Why didn't he support her?

Here's Matthew K. Johnson:

For those of us who follow foreign policy and human rights policy in particular, Samantha Power is a fascinating and inspiring figure - a brilliant woman who has lectured and written equally from her heart and her head. Her Pulitzer-prize winning book A Problem From Hell is a passionately argued and beautifully written description of America's at times shameful and always complicated history during the genocides of the 20th century - it remains my favorite non-fiction book; the first one I will recommend to friends and colleagues and has inspired more than one of my own written works.... Her profession, and her approach to it, makes her a somewhat undiplomatic politcian, but I was still absolutely thrilled that she joined Obama's campaign, and was one of the first reasons that I became an Obama supporter - clearly he was attracting the top minds, many of whom were critical of the practices of the past (Power, like myself, is very critical of the Clinton years - the inaction on Rwanda, the ignorance of the power of strong leadership in the Balkans).

What do we learn from this incident? I don't need to learn that Clinton will do whatever it takes to win, and perhaps that does earn the label "monster," but let's not ignore the deficiencies in Barack Obama. How does he intend to win by shrinking away when her people pull their tricks? Where is his vigor? And, more importantly, where is his courage? It was cowardly to allow the Clinton campaign to savage Power and rip her away from him.

And now I'm wondering whether there is anything courageous about Barack Obama. Obama supporters, please: Make the case to me that the man has courage. And don't say that he opposed the war in Iraq, because I don't think, in the position he was in at the time, that it took courage to oppose the war. That served his political ambitions. Tell me something he did that was difficult to do, that took some risk to do what was right.

IN THE COMMENTS: Balfegor said:

I've read speculation that he may have used the "monster" kerfluffle as cover for tossing her overboard because in that same interview, she claimed he wasn't actually serious about getting out of Iraq in 16 months or whatever his plan was -- once he was president he'd discard his campaign plan and take a new look at the situation.

If this is the reason he let her go, it's a defense against the charge that he let Hillary push him around, but it only makes me worry more that he lacks courage. And ironically, Power's statement about how he would handle Iraq reinforced what I've been assuming, and this assumption was central to my decision to vote for him in the Wisconsin primary.

So what am I to think now that he let Power go? That what she said about Iraq was wrong or that it was right? If it's wrong, I like him less on policy. If it's right, then I'm more upset about the estrangement of Power and concerned that Obama is dishonest, saying things to get elected that he's never going to do in office. And yet — this is so troublesome for me! — I'm hoping that, if elected, he'll listen and reassess and exercise the good judgment that he now applies to the task of getting elected and the results of his presidential decisionmaking will be much more to my liking.