The central U.S. state of Iowa, and several other states, have an alternative way to select presidential nominees for the Democratic and Republican parties. In this segment of "How America Elects," VOA's Jeffrey Young explains how a caucus differs from a primary election.

The blazing summer heat is long gone, but in Iowa and some other states, presidential politics remains red hot. And now, it is time to make decisions.

Iowa makes the first official decisions of the 2008 White House race. Iowa, and several other states, do not hold initial, or primary elections for selecting presidential candidates. They use a different system, called a caucus.

Caucuses are more complicated than a primary election, as Benjamin Ginsberg at Johns Hopkins University explains.

"People registered in a particular political party assemble in a variety of places across the state," he says. "And there, they discuss, they debate, and at the end of the evening, a vote is taken of those assembled. And then all of those votes from across the state are tallied."

These votes determine how many delegates supporting each candidate will go to the convention that nominates that party's official presidential contender.

The caucus process requires candidates to work hard in every corner of the state to round up supporters, as Democrat John Edwards demonstrated in 2004.

"I came here to ask you to caucus for me. I need you. I cannot do this without you. I need you to get your friends, your family, your neighbors to the caucuses," he said. 

And, as this John Kerry campaign worker from 2004 explains, caucuses, unlike primaries, do not always begin with firm candidate decisions.

"They have not quite made up their mind, and probably, people do not want to say they made up their mind. They want to be convinced up to the last minute. But they are listening."

There are political observers who contend that caucuses produce very skewed results.

"Caucuses definitely do not represent the electorate at large," says Mark Rom at Georgetown University. "Those people who will devote the time and attention to go to the caucuses are the most partisan members of the electorate. Republicans tend to be much more conservative than the electorate [at large], if they go to the caucuses. Democrats tend to be much more liberal than the electorate [at large], those who go to the caucuses."

But others see the caucus system as being closer to a democratic ideal. That is the view of Lorenzo Morris at Howard University.

"It is true that caucuses not only reflect opinion, they [also] form opinion. And that is the ideal of a democracy - that people do not come to any encounter with their own opinions absolutely, but [instead] are open to exchange and discussion so that you build on the pluralistic diversity. Different segments [and] different interests, but they find a common denominator," Morris said. 

For Iowa, what really matters above all is that it selects candidates, and their convention delegates, first among all of the states, before the first primary election is held in the northeastern state of New Hampshire.