By Scott Conroy - December 27, 2011

A week from today, somewhere between 80,000 to 150,000 Iowans are expected to head to their local precincts to participate in the caucus system that has governed the state's politics since the mid-1800s.

Even if turnout far exceeds projections, only a small percentage of Iowa’s 3 million residents will participate in the event that plays an outsized role in determining which Republican candidate will face off against President Obama in November -- and possibly lead more than 300 million Americans over the next four years.

Despite the national media saturation, the process by which the Iowa caucuses are run can seem incomprehensible even to politically attuned outsiders, and it is rarely explained in detail.

But some quintessential Iowa quirks notwithstanding, the Republican caucuses are rather straightforward.

Iowans who wish to participate on Jan. 3 must first find the voting site of their local precinct. The venues tend to change every four years, so even longtime caucus-goers are advised to double-check with one of the campaigns, the Iowa Republican Party website, or their local newspaper.

There are 1,774 precincts in this year’s caucuses, and many of the state’s rural outposts will see just a trickle of participants. On the other hand, some of the more populous counties combine their precincts into one location, which means that thousands of caucus-goers will gather at a single location.

Blackhawk County, for instance, is holding this year’s caucuses at the UNI-Dome, where the University of Northern Iowa football team plays its home games.

The gatherings are run entirely by the state Republican Party, which will deliver to each precinct a list of registered Republicans as of Nov. 14.

Once people start arriving at their caucus sites, they will be checked in and directed to their seats if they are already registered with the party. Non-Republican voters are allowed to register on site with the GOP upon providing a driver’s license or other photo ID with proof of residency and will be added instantly to the party’s registration rolls and can participate that night.

Seventeen-year-olds who will turn 18 by Nov. 6, 2012 are allowed to take part.

Refreshments are typically provided, and neighbors and friends will mingle before the session is called to order by a volunteer precinct captain.

The caucuses begin at 7 p.m. Central Time, but Iowa GOP officials and the campaigns themselves encourage voters to show up early, since the process typically starts on time. Michele Bachmann’s website, for instance, directs supporters to be at their caucus precincts by 6:30 p.m. and does not mention that the event actually begins a half-hour later.

After a few minutes of procedural business, the captains will move on to the main event: the Presidential Preference Poll.

Each campaign will then be allowed to have one surrogate speak on its behalf. These speeches, which typically last two to three minutes, are among the most important elements of the entire process and figure to be even more critical this year, given the especially high percentage of undecided voters.

“I hope to make a decision before I go in there, but a lot of people will actually go in there, visit with their neighbors not knowing what they’re going to do, and say, ‘Who do you support?’ ” said longtime Iowa Republican activist Becky Beach. “And what happens a lot is people who they are friends with or that they respect, they’ll vote with those people because they know them and like them.”

In the past, well-organized campaigns have placed volunteer speech-givers at almost all of Iowa’s precincts, providing them with talking points for closing the deal.