The caucuses serve two important roles. The first is to choose a candidate; the second is to set the party platform. That second part is arcane and hard to report and hard to sell in headlines, so it doesn't really get any press coverage -- everything's all about the candidate.
Every state has a caucus for every political party. You're only hearing about the Dems this year because Bush is the candidate-apparent for the GOP, and nobody viable is running in any of the third parties. Iowa's caucus gets so much attention because it's the first one; there's really no other reason. It's the first time there are any cold hard facts about who's likely to be the Presidential candidate instead of just a bunch of phone polls.
OK this next part gets a little hard to follow, so stay with me.
Each state gets a certain number of delegates, which are the folks who actually vote for the candidate of their choice. It's based on population, so California has like a zillion, while Wyoming has, like. . .. two. OK more than two. But this isn't a majority rules election, where the most popular guy gets all the votes; it's what's called proportional representation, where if 30% of your state's population likes candidate X, then 30% of your delegates will be for candidate X.
The way they sort this out is that in every voting precinct, everyone who cares gets together and splits up into groups depending on who they like. Then they figure out what percentage is for who, and choose their delegates as a result. (The delegates btw are real people who just happened to show up that day and are willing to go on to the next convention. They aren't like special politics people.) There's an additional confusing thing where a candidate has to have at least 15% in order to get any delegates at all, too. If someone gets less than 15% of the vote in any given precinct, than all of his delegates have to decide who they like second best and go throw their lot in with that guy.
At the end of the primary, the guy with the most number of delegates NATIONWIDE is the guy who gets to be the presidential candidate. So it's possible, by some unlikely math, for the guy who comes in second everywhere to be the candidate. All of you should go to your caucus; it's free, and it's fun, and it gets you involved in politics at a grass-roots level. Even if you're not picking a candidate because you're a Republican or whatever, you still get to say your piece about what should be in the party platform, and that's always good.
You know, I thought I had a very basic grasp of politics and all that, I sorta understood the "importance" of the Iowa caucus and all that... but I've NEVER seen it explained in plain English! That was so helpful - thankyou thankyou thankyou!
In most states, you become a Senator by getting about 1000-5000 signatures on a nominating form and then running. Oh, and you have to be 35 years old, according to the Constitution. That's it. All the other stuff -- getting your party's endorsement, fundraising, getting endorsements from groups like the AFL-CIO, advertising, campaigning -- is all not officially a legal thang. Actually, I heard about a guy who collected unemployment by running for President. He collected enough signatures to be on the ballot in one state, and then he showed the unemployment office he was looking for work by making posters, talking to friends about why he would be a good President, and all that sort of thing.
In some states, such as Indiana, the delegates are a "winner-takes-all" format. If more than half of the popular vote is for candidate X, then all the delegates vote for that person for President. They don't split the delegates' votes by percentage. Now you may see how someone can win the popular vote in the whole nation and not win the Presidency.
So, can you give us the thumbnail schedule for the primaries, and the convention? Also, as much as Iowa and NH get tons of press, they don't have big delegations, thus aren't nearly as important to winning the nomination. How do the states delegates breakdown? I know Cali's got like a zillion.
Best place to get information like that is to look at your party website. Democrats are http://www.democrats.org; Republicans are http://www.rnc.org. They'll have all the info you're looking for there.
I've lived in Des Moines, Iowa all my life and never cared about or understood the caucus process. I always thought of it as just a big politics/media mess that happened every four years; I sincerely wished it would all just go away by having some other state trump Iowa by scheduling their caucus/primary before ours. Hasn't happened, but now at least I comprehend the whole process much better. Thanks, Kathryn, for explaining it so well.