What Will the New Hampshire Surprise Be This Year?

People vote at the Canterbury, New Hampshire, Town Hall polling station on Tuesday. Often, the winner in Iowa loses the following week in New Hampshire, but with 40 percent of the voters being undecided, the outcome tonight could surprise us. Shannon Stapleton/Reuters

This article first appeared on the London School of Economics US Centre site.

In the lead-up to today's New Hampshire primary, some pundits have been predicting that snow might have a big impact on turnout, while others are not so sure.

This is no surprise; the New Hampshire primary is a veritable graveyard for such predictions. Time and again, the voters in the Granite State have scrambled the presidential race. Often, the winner in Iowa loses the following week in New Hampshire.

It happened to Barack Obama in 2008. He beat Hillary Clinton in Iowa only to see her come back in New Hampshire. The same thing happened in 2012 on the Republican side. Mitt Romney lost to Rick Santorum, but came back strong in New Hampshire.

Much of this has to do with New Hampshire's voting rules. Undeclared voters can vote in either the Republican or the Democratic primary. These voters often break late, strategically looking to see where their vote is likely to count the most.

This year, roughly 40 percent of New Hampshire voters are undeclared. That's a large number, and while many observers expect them to vote in the Republican primary, they might surprise us.

Could Trump lose (again) in New Hampshire? What about Bernie Sanders?

Yes, anything is possible. Trump could lose; Sanders too. But right now Trump and Sanders are leading in all of the New Hampshire polls, and if you had to bet, you'd bet on both of them to win. I think the more interesting questions are by how much and whether their victories will change the dynamics of the race.

On the Republican side, the key question is whether one of the moderate Governors—Kasich (Ohio), Bush (former, Florida) or Christie (New Jersey)—is able to beat expectations. Kasich is trending upward in most of the polls, so he may be the one to watch.

On the Democratic side, Clinton is also closing the gap in the polls and if she comes close, it will breathe new life into her campaign as we move on to South Carolina, where the demographics are more favorable for her than for Sanders.

Will New Hampshire fundamentally alter the course of the presidential campaign?

Probably not. On the Republican side, I expect most of the candidates to hang in there until at least South Carolina and possibly, Super Tuesday in early March. Christie and Kasich are the most likely to exit, should they fail to meet or beat expectations today.

On the Democratic side, Clinton and Sanders will soldier on, no matter who wins today. What could change the dynamic is if Trump's vote evaporates or Clinton runs a distant second.

A Trump loss would open things up for others, though it is not obvious who Trump supporters, many of whom are blue collar, would line up behind. A poor showing by Clinton would raise anew questions about her viability in a party that has a strong progressive wing.

Peter Trubowitz is professor of international relations at the London School of Economics (LSE) and director of the LSE's US Centre.