Time's Tumulty on Hillary's five big mistakes is a good read. But let me offer a candidate for number six: Standing by her Iraq vote. Hillary made it clear that, knowing what she knows now, she would not have voted to authorize the war in October 2002. But she never flat-out apologized for her vote. Let's flash back to February 2007:

One of the most important decisions that Senator Hillary Rodham Clinton made about her bid for the presidency came late last year when she ended a debate in her camp over whether she should repudiate her 2002 vote authorizing military action in Iraq.

Several advisers, friends and donors said in interviews that they had urged her to call her vote a mistake in order to appease antiwar Democrats... Yet Mrs. Clinton herself, backed by another faction, never wanted to apologize — even if she viewed the war as a mistake — arguing that an apology would be a gimmick.

In the end, she settled on language that was similar to Senator John Kerry’s when he was the Democratic nominee in 2004: that if she had known in 2002 what she knows now about Iraqi weaponry, she would never have voted for the Senate resolution authorizing force.

Yet antiwar anger has festered, and yesterday morning Mrs. Clinton rolled out a new response to those demanding contrition: She said she was willing to lose support from voters rather than make an apology she did not believe in.

“If the most important thing to any of you is choosing someone who did not cast that vote or has said his vote was a mistake, then there are others to choose from,” Mrs. Clinton told an audience in Dover, N.H., in a veiled reference to two rivals for the nomination, Senator Barack Obama of Illinois and former Senator John Edwards of North Carolina.

Her decision not to apologize is regarded so seriously within her campaign that some advisers believe it will be remembered as a turning point in the race: either ultimately galvanizing voters against her (if she loses the nomination), or highlighting her resolve and her willingness to buck Democratic conventional wisdom (if she wins).

Early in the campaign, Hillary spent a fair amount of time defending and justifying her vote; think back to her discussions about executive authority. In hindsight, I think this may have been a fatal error by her campaign. Iraq was the initial wind under Obama's wings, and really laid the groundwork for his entire candidacy. Democrats wanted someone whose hands were totally unsullied by the war, who could claim to be a break from the Washington thinking that got us there, and who could be a vessel for the primary electorate's pent-up frustrations towards Democrats perceived to have sold out in the early Bush years. Of course, Hillary couldn't have undone her vote.  But taking John Edwards's stark "I was wrong" approach might have blunted the damage. 

One reason Hillary never did this is because some of her key advisors believed disowning her vote would have looked like a Clintonian flip-flop. But the other reason may be that she actually believed in what she was doing.

--Michael Crowley