The first real vote in the race for President of the United States occurs tonight when the citizens of Iowa hold their caucus.

So, how does the Iowa Caucus work?

Democrats and the Republicans each hold their own caucuses and each has their own distinct process.

Democratic Party Process

• Each candidate's supporters stand in a specifically designated space in the caucus location at their local precinct (undecided attendees may also have their own space).
• Supporters then campaign to recruit more supporters for their chosen candidate for a given amount of time (about half an hour).
• Once the time for recruitment has elapsed, a head count is taken; and all candidates must have enough supporters to remain viable (15% of attendees).
• A realignment of supporters occurs (supporters of unviable candidates can choose another candidate to support or decide to abstain). This process takes about half an hour as well.
• A final count is then taken of all supporters and delegates are apportioned to the county convention.
• The number of the county convention delegates at each precinct is tallied and the media declares the winner.

Republican Party process

• Each attendee is given a blank sheet of paper.
• Supporters campaign to recruit more supporters for their chosen candidate for a given amount of time.
• Attendees then write the name of the candidate they are choosing to support on the blank sheet of paper.
• The Iowa Republican party tallies the votes at each precinct.
• The results are submitted to the Iowa Republican party at the state level and the media declares the winner.

Caucus participants are also charged with kicking off the writing of their respective party’s platforms by introducing resolutions. They also must select delegates to county conventions, who in turn select delegates to district and state conventions where the final national convention delegates are selected.

Iowa has 1784 precincts and 99 counties.

Source: http://www.iowacaucus.org/iacaucus.html