The whole presidential primary system is complex, and I don't pretend to fully grasp how it works. But that's mostly because I've never lived anywhere where it mattered. In 2004, the Michigan caucus was in mid-March, and Kerry was already running away with it. My Dean vote was merely symbolic—it didn't mean anything.
Not this time. Michigan is in play, and that means candidates will be coming here to press flesh—good, and bombard me with advertising—bad. All I can say, is I cannot wait to vote, and have it matter. And that's (probably) bad news for Hillary.
This diary at Kos breaks it all down.