Realistically, the Iowa Caucuses are a ridiculous measure of the electorate. It's a massively flawed system in an absurdly unrepresentative state. But none of that matters. What matters is how the media spin it, and what happened tonight will be easy for their simplistic framing: Obama won big, Hillary sputtered to a weak third place, not even breaking 30%. Edwards really needed to win, and didn't.
Keep an eye on the New Hampshire polls. The media want this to give Obama a big bump. It probably will. The size of his win in this massively flawed system in this absurdly unrepresentative state makes him the clear frontrunner for the Democratic nomination. Hillary polls far ahead, in later states, but that could quickly erode. The pressure is on her to do much better in New Hampshire. Even a close loss might not be enough. If Obama carries this big win into a second win, next week, he may be unstoppable.
It's tough to see where Edwards goes, from here. He's not polling well in New Hampshire or South Carolina, and he needed a big boost, to get any traction in either. He didn't get it. His campaign is in serious trouble. Should he be out, after South Carolina, it will be interesting to see what his supporters do. None are more passionate. If they move as a bloc, they could make the difference.
Obama's centrist strategy worked, in Iowa. It's not popular with many die-hard liberals. If the only alternative turns out to be Hillary, where do they go? Obama also proved enormously inspiring to young voters. Should he win the nomination, they could help sweep Democrats into all levels of offices. Such a Democratic landslide could mean a much more liberal Obama Administration than many now fear.
In the end, though, this race is far from over. Bill Clinton was known as the Comeback Kid. We'll now find out if Hillary has similar skill and tenacity. She won't go down easily.