5 Things That Could Define the 2016 Iowa Caucuses

DES MOINES, IA— -- The 2016 Iowa caucuses have all the makings of an historic night for Democrats and Republicans, with a real possibility the current two frontrunners Hillary Clinton and Donald Trump could be beaten in what remains a very close race.

It's been an election that has in many way re-defined American politics and the way campaigns are run. So when all things are said and done, what are the major storylines you should watch out for tonight as the results are pouring in?

1. High Turnout Bodes Well for Bernie Sanders and Donald Trump

The big question surrounding the Republican race is whether Donald Trump's supporters will show up to caucus or avoid the process altogether. In a caucus, there's no absentee ballots or a full business day dedicated to voting, allowing Americans to head to the polls before, during, or after work. You have to physically go to a location at 7 p.m. CT in your neighborhood, even if the temperatures are cold and a snow storm is looming. Caucuses can also last two hours.

With a strong ground game, offices all over the state, and more than 10,000 volunteers, Bernie Sanders can expect to have his support out in force. But where they caucus and if that voting is too concentrated in certain areas is the big question.

The key for both Sanders and Trump is motivating the first-time caucus-goers they've been able to bring to their Iowa events to come out in large numbers, similar to what happened in 2008, when turnout doubled.

2. Where Will Romney 2012 Voters Turn?

Mitt Romney, an establishment Republican, nearly won in Iowa in 2012, losing to Rick Santorum by only 34 votes, receiving 25 percent of the vote in Iowa. But it remains to be seen which 2016 candidate will get the votes of the type of people who supported Romney.

The candidates who hold the most similar policy positions to Romney are John Kasich, Jeb Bush, and Chris Christie, who are all polling in the low single digits in Iowa. All three are spending caucus night in New Hampshire, where they're polling higher. Some Iowa Republican strategists say that 25 percent could be split between Marco Rubio and Donald Trump, but that segment of voters could be key to boosting Trump over Ted Cruz.

3. Poor Iowa Performances and the Dropout Effect

Rick Santorum and Mike Huckabee, both past winners in Iowa, have not picked up any traction in 2016, even after they both made the state a centerpiece of their campaigns. With both of them low on funding, it will be difficult for either to continue on without placing in the top three.

In late December, on Iowa's WHO radio, Huckabee said: "If we can't come within striking distance of the victory or win it, then I think we recognize that it's going to be hard to take that on to the other states."

But Sunday night at a house party in Iowa, Santorum told reporters he has "no intention of dropping out of the race."

On the Democratic side, Martin O'Malley has held 187 events in Iowa, but has not been able to go above 4 percent in the polls and could call it quits if things don't go his way.

4. What a Trump Victory Means for the Future of the Caucuses