The first votes for the 2016 presidential election will be cast Monday night at the Iowa caucuses, then at the country’s first presidential primary eight days later in New Hampshire.
Hillary Clinton, Ted Cruz, Bernie Sanders, Donald Trump and other White House hopefuls have turned both states into their homes-away-from-home, stumping for support nearly every day for the past several months.
But one question lingers among out-of-state voters: How exactly does the Iowa caucus work? And how is it different from the primary a week later in New Hampshire?
Here's what you should know as the presidential nomination process kicks off.
Iowa caucuses: What happens Monday
In Iowa, groups of voters will meet in 1,681 precincts throughout the state beginning at 7 p.m. local time Monday.
“It’s basically a gathering of neighbors, so it’s the folks on your street or in your neighborhood or at your church who vote at the same place where you vote, coming together to discuss politics,” said David Redlawsk, a political science professor at Rutgers University currently serving as a fellow at Iowa’s Drake University.
The caucuses will take place at schools, fire stations, city halls and sometimes churches — any easily accessible public location.
Attendees must caucus with their political party, but individuals can register to vote that same day, or even upon entering the caucus that evening. Each side gathers and may hear from a candidate supporter or surrogate.
From there, it varies widely between parties.
Why Iowa is different for Democrats
Republicans cast secret ballots, but Democrats go through a far more complex process.
“Democrats have to be willing to stand up in front of their friends and neighbors and say, 'I’m supporting Bernie Sanders. Or Hillary Clinton. Or Martin O’Malley,'” Redlawsk said. “They will literally, once the caucus is called to order, physically move to different parts of the room to show their support.”
The larger the preference group the better because Democrats require candidates to garner at least 15 percent of support per precinct.
And that’s when Iowa voters may find themselves appealing to a neighbor — or good friend or colleague — to join their side.
Supporters of candidates who fail to meet that threshold may campaign to gain additional voters, or they may choose to walk over and join those supporting the remaining candidates. The percentage of support is crucial because it determines how many delegates are awarded to each viable candidate.
“So somebody might have set support across the state, but if they’re not viable in very many precincts, they might not get any delegates, or very few, at the end of the night,” said Tim Hagle, political science professor at the University of Iowa.
Republicans, meanwhile, have it much easier at their caucuses: Voters write the name of their favored candidate on slips of paper that get collected and tallied. The group then moves on to party business.
Does an Iowa victory guarantee a party nomination?
Winning Iowa may provide bragging rights (and a publicity boost) for candidates, but it doesn’t always foreshadow who will win the party nomination.
Rick Santorum emerged victorious in 2012 from the Republican Iowa caucuses, as did Mike Huckabee in 2008, but neither became the party’s nominee.
On the flip side, George W. Bush won Iowa both times he ran for president, as did Barack Obama. And while John Kerry may not have won the 2004 general election, he did win both the Iowa caucuses and the Democratic nomination that year.
“I tell people the purpose of the Iowa caucuses is to winnow the field,” said Tim Hagle, political science professor at the University of Iowa. “Or another phrase I use is 'to separate the contenders from the pretenders' — the people who are serious candidates from those who aren’t. In that sense, Iowa does a pretty good job.”
New Hampshire also serves a similar purpose.
Iowa and New Hampshire are both small states: Why that matters
Unlike Iowa, the Granite State holds a primary election, a system used in most states. This year on Feb. 9, voters will have all day to head to polls and cast ballots directly for their candidate.
There's a similar theme voters in both states should remember: Love thy neighbor. It just might help your candidate become the next president.
“The caucuses are really about community and neighborhood gatherings and talking politics. But in the end, the campaign in New Hampshire is very similar to the campaign in Iowa — it’s very personal, it’s very oriented around town halls and one-on-ones,” Redlawsk said.
And both states are small, providing certain advantages to the candidates, Hagle said.
“Iowa in particular is an inexpensive state to run in, so you can have a candidate who doesn’t have billions of dollars, come in and work hard, do some ground, build support and ultimately win," he said. "That’s basically what Santorum did four years ago when he ran his campaign on a shoe string."
Both states also give candidates a chance to get practice campaigning on a smaller scale, Hagle said.
“It gives them an opportunity to do the one-on-one retail politics that they really can’t do once their campaign expands,” he said. “The candidates then show up at events, but they’re generally bigger and don’t give voters that opportunity to ask the kinds of good, perceptive questions you’re seeing now in the early stages of the game.
“Overall, that’s a significant benefit to the people as a whole, not just those in Iowa and New Hampshire.”
Follow TODAY.com writer Eun Kyung Kim on Twitter at @eunkim.