Where did the Hillary Clinton campaign first go wrong? How did she go from inevitable to in trouble?
I think it all began with the very first contest: Iowa.
Iowa is where Clinton needed to strangle the Barack Obama campaign in its crib.
She needed to do him in at the very beginning, while her inevitability argument still had credibility.
True, some in the Clinton campaign were worried about Iowa. Mike Henry, her deputy campaign manager, wrote a 1,500-word internal memo saying Clinton should skip the state entirely and spend her time and money elsewhere.
Bill Clinton had not run in Iowa in 1992 because Iowa Sen. Tom Harkin was running as a favorite son, so Hillary had no organization to build on. Secondly, Iowa did not seem all that welcoming to women candidates.
"I was shocked when I learned Iowa and Mississippi have never elected a woman governor, senator or member of Congress," Hillary Clinton told Des Moines Register columnist David Yepsen in October 2007. "There has got to be something at work here."
But Obama did not have an organization to build on, either. And though he was a man, he was also an African-American in a state that is 94.6 percent white.
And Clinton did have some advantages: Older voters favored her, and Iowa was a state with a lot of older voters. In 2004, voters over the age of 50 represented a whopping 64 percent of those who voted in the caucus.
Further, because it was a caucus state, Clinton was supposed to do well in Iowa. Caucus states stress organization more than primary states do, and she was sure to have the best organization, wasn't she? (It was not until after Iowa that the Clinton campaign began complaining that caucuses were "undemocratic.")
Clinton's campaign strategy in Iowa was a traditional one: Target those voters who had voted in the past the most reliable kind of voters there are and then get them to the polls. And some Clinton aides were openly contemptuous of Obama's attempt to "expand the universe" and bring in younger voters.
Young voters simply don't vote, they said. They may show up and wave signs at rallies, but they don't vote. Everybody knew that.
Except in Iowa, in January of this year, they did vote. Younger voters represented 22 percent of the vote in the Iowa caucus the highest youth turnout in any state so far and Obama got 57 percent of them to Clinton's 11 percent. The youth vote, in fact, turned out to be about 30 percent of Obama's total vote.
At the end of the day, Obama won 38 percent of the delegates at stake, John Edwards got 30 percent, and Clinton fell to earth with a thud, in third place with 29 percent.
I went on "Lou Dobbs Tonight" after Clinton's loss in Iowa and said: "She is looking into the abyss, and the abyss is looking back."
Which was a pretty ridiculous thing to say, right? (Jon Stewart thought so, anyway. He ran the clip on "The Daily Show" to prove it, and he tends to be right.) After all, Iowa was only one contest, and the first contest, at that. And Clinton immediately went on to beat Obama in New Hampshire by 2.6 percentage points.
But to my way of thinking, Clinton's loss in Iowa was a critical one, because she was no longer inevitable. She had let Obama into the game. She had let a candidate with money and a message get off to a running start. She had allowed him to become a credible candidate.
And, as it turned out, her campaign had no real strategy for what to do next. The Clinton campaign had no midgame strategy what to do after Super Tuesday because the campaign was sure that after Super Tuesday, Obama would be finished, brushed away like a pesky mosquito.
As it turned out, Obama had both a strategy and the money to execute it. His campaign knew what the race really was about: the acquisition of pledged delegates.
I look forward to the books that will analyze this election Dan Balz and Haynes Johnson are co-authoring a book for Viking because they will be able to give it the perspective it deserves.
But for me, for now, Iowa is still the pivotal moment.
"We had a plan, and that plan was always to focus on Iowa," David Axelrod, Obama's chief strategist, told me this week. "Iowa was our gateway to the nomination."
It is important to win early. It is important to win often. And this time, it was important to win first.