Howard Dean didn't do anything wrong in that campaign. He was saying the right things, doing the right things, and had absolutely the right positions on all the important issues in the campaign. He took the term "grass roots campaign" to unprecedented heights, reinventing the use of the internet in national political campaigns with his "meet-ups", "blogs", and grass roots fundraising which raised tens of millions of dollars thru small grass roots contributions from millions of supporters across this nation (which has since been widely copied).
What happened was that when it became evident in the 4th quarter of 2003 that Dean was the people's favorite candidate to become the next president, two powerful forces swung into action with a coordinated effort to prevent him from becoming the Democratic nominee: 1) The Clinton-dominated DLC (Al From, Bruce Reed, Harold Ford, James Carville, etc) whose #1 goal was really to make sure that George W Bush was given a 2nd term, whereby they knew he would fuck up the country even more....no matter the damage it would do to the country during the next four years...in order to clear the deck for any Democrat...who they assumed would be Hillary Clinton...to be easily elected in 2008. And that is exactly what happened, except the one thing they didn't plan on was the emergence of Barack Obama on the scene. And, 2) The National Media which is constantly & erroneously thought of as being "liberal"...but which is really a pawn of the establish power structure in the country...readily lined up to assist them.
I was heavily involved in the Dean Campaign from February, 2003 until its conclusion....attending more than 20 campaign functions during 2003 and contributing the maximum allowed contributions to his campaign. People who were not following the campaign closely mistakenly point to the "Iowa Scream" speech as the act that cost Dean the nomination....but the coordinated attack on Howard Dean from the DLC & National Media began well before that with a constant strategy of suggesting that Dean was "too angry" to be president. So by the time the Iowa caucuses occurred, Dean had slipped from 1st in earlier polls in Iowa to an ultimate 3rd place finish....almost entirely due to this "anger strategy" whisper campaign being employed against him. Then they used sophisticated electronic equipment that could mute background noise in a loud, crowded atmosphere to make it appear that Dean was exactly this "angry" candidate that they had been caricaturing for the last 6 to 8 weeks since Dean's poll ratings had reached dominant levels and many top Democratic officials (including Vice President Gore & President Carter) had endorsed him. That's really when the Clinton-DLC & National Media swung into action against him. It didn't just start that night after the Iowa caucus. And, finally, the National Media dutifully replayed that sound-rigged clip over & over & over again in the coming weeks.