Iowa and New Hampshire might seem the same, but they are very different.

To much of the country, the early election contests of Iowa, January 3, and New Hampshire, January 8, appear as two largely white, non-urban, voting populations, which are lavished with an inordinate amount of attention every four years from presidential candidates and celebrities, such as Oprah Winfrey, who visited these places this weekend.

Upon further examination of these two states though, there are many qualities that distinguish them.

In New Hampshire, the polls will be open a minimum of eight hours on election day, between 11 a.m. and 7 p.m. Voting in most communities begins far earlier, such as the 6 start in Manchester. In Iowa, caucuses begin at 6:30 p.m., and voters have until 7 p.m. to arrive for their vote to be counted.

New Hampshire, like most states, allows voters to submit absentee ballots. New Hampshire’s secretary of state has already distributed those ballots to cities and towns. Voting can begin soon. Iowa’s caucus, however, permits no absentee ballots. The demands of the caucus are such that voters must go in person to the meeting place for their precinct at the appointed time and stay until the process is complete.

In New Hampshire, members of the armed services can vote. Soldiers and marines fighting in Iraq and Afghanistan have the same opportunity to cast their votes as veterans of the Korean War. Iowa’s arcane caucus requirements permit no voting-by-proxy which leaves those serving their country out-of-luck and without a franchise in this important contest. Likewise, the caucuses pose a problem for night workers and the elderly, among others.

The short window of time for voters to cast their preference in Iowa prevents campaigns with strong organizations from doing the traditional things they do to make sure voters who have expressed interest in their candidates actually vote. A campaign can check to see if voters have taken part. If they haven’t, they can make sure they get to the polling place a bit later on election day. The half-hour window in a caucus doesn’t provide enough time to do this.

There also is a difference for those who turn out on election day in the two states. In 2004, almost 30% of New Hampshire’s electorate voted, according to the Century Foundation. A mere 6% of eligible voters participated in the Iowa caucuses in 2004. “Legitimate, eligible, and indeed interested members of the community get left out of the caucuses,” a foundation’s fellow Tova Wang, said in a press release about her study, “Has America Outgrown the Caucus?” published this October.

There have been some improvements made to the caucuses over time. Voters as young as 17 can vote, so long as they’ll be 18 as of the general election in November. An individual who has not registered to vote can show up at a meeting place, fill out some paper work, and be able to cast a vote. This is not enough though.

Few journalists know as much about the Iowa caucuses as David Yepsen, who as the chief political correspondent for “The Des Moines Register” has been covering the election for 33 years. He says the people who show up on caucus day are party activists who resemble delegates at national party conventions. “You’ve got to care. You’ve got to be motivated,” he said.

Although not much is being said yet about elements that make Iowa and New Hampshire distinct, come the first week in January that will change. “You’ll hear a lot from losing candidates to discredit the results,” Mr. Yepsen says.

Something else differentiates Iowa and New Hampshire. The Clintons have a history in New Hampshire, but not in Iowa. In 1992, Bill Clinton opted out of participating in Iowa, where the native Senator Harkin won 76% of the Democratic vote. That same year, Mr. Clinton closed to within nine percentage points of Massachusetts’s Paul Tsongas, who won the primary and emerged “The Comeback Kid.”

A recent MSNBC poll shows Mrs. Clinton leading Mr. Obama by a slight 2% in Iowa. How she navigates the strange battleground of Iowa will help to define the presidential race.

Mr. Gitell (gitell.com) is a contributing editor of The New York Sun.