What exactly is a Caucus and who attends?

FOX News Radio's Rich Johnson has the answer from America's Election Headquarters in Des Moines:

From America's Election Headquarters:

Iowa voter: "It is a pain in the butt. If you could watch 'em online it would be good (laughs)."

But that Iowa voter will have to get out of the house Tuesday night if she wants to participate in her local caucus.  It's basically a meeting of registered party members to talk policy, organize, and every four years, pick a Presidential preference.

So who goes?

Strawn: "Usually middle aged, senior citizen, married, church going, social economic conservative."

Iowa State GOP Chair Matt Strawn says registered Republicans will hear from Candidates' supporters; each limited to five minutes.  Then they're handed a blank piece of paper and they write in their choice.  And that's it.  No second or third ballots, as the Democrats do.  And yes, the Democrats are also caucusing.  And for those not feeling up to it mentally, this advice:

 "Throw some e-books on your iPad, read 'em for a little bit, and when you hear something interesting, pay attention."

In Des Moines, Rich Johnson, FOX News Radio.