National polls gauging the US presidential election are tightening as Republican partisans fall in line behind their party’s controversial nominee, Donald Trump. But it’s the state results that matter in the race to rack up enough delegates to clinch the White House.

The fear for some Democrats is that Hillary Clinton has been working too hard to expand the blue portion of the map to places like Arizona, while taking some of core states she needs to win a bit, well, for granted.

Sure enough, three new polls published today showed gains for Trump in the small New England state of New Hampshire, speaking to the outsized importance of voters there this year.

New Hampshire is a unique state politically, combining a mix of influences: libertarian activists, a rich Republican tradition, proximity to liberal Massachusetts, a growing high-tech industry, and the presence of Dartmouth College and several other higher-ed institutions. Today, the state boasts a Democratic governor and equally splits its two senators and two representatives between the two parties. Its voters have backed Democrats for president in every election since 2000, when they went for Republican George W. Bush by a margin of less than two percentage points. If Democratic candidate Al Gore had won the state that year, all that controversy in Florida would have been moot.

A similar scenario, with a loss in New Hampshire throwing the electoral college into a tie or knocking out Clinton altogether, would be a nightmare for Clinton’s campaign. While months of surveys average to a 7-point lead for Clinton in New Hampshire, but of the four new polls published today, one shows her in a tie with Trump, another shows her losing to Trump by 1 percentage point, another losing by 5 percentage points, and the last has her leading by 10 points. Those first three polls might be outliers, but they also suggest that the national tightening is being replicated in the state, a warning to Clinton’s field team.

In the primaries, New Hampshire gave Trump his first victory, and the electorate is arguably favorable ground for him because of its high percentage of white residents without college degrees. Clinton, on the other hand, has ties in the state reaching back to when it made her husband a “comeback kid” during the 1992 presidential primaries, and voted for him in both of his White House races.

The state’s jealously guarded status as the first to vote in presidential primary elections (Iowa has caucuses) frequently leads to criticism because the New Hampshire electorate isn’t particularly representative of the nation at large for all the influence it is afforded. Yet, according to calculations by Princeton statistician Sam Wang, the most meaningful votes in the country are cast in New Hampshire, because of how closely balanced the two parties are there.

The calculation is simple: Everyone is familiar with the idea that in states where one party is enormously favored, the result won’t be affected too much by your one vote. But in states where the outcome is far less certain, each vote is more meaningful. The meaningfulness of votes in New Hampshire extend beyond the presidential portion of the ticket. A pivotal senate race in New Hampshire between Republican Kelly Ayotte and Democrat Maggie Hassan is equally tight, and could decide which party controls the US legislative chamber in 2017. In a nation on a knife-edge, the Granite State is the pivot point.

For this reason, Clinton hasn’t been taking the state lightly. She and her allies have spent $28 million on television ads there, versus $9 million from Trump. She held rallies in the state with neighboring senators Elizabeth Warren and Bernie Sanders in October and September, respectively. And her daughter, Chelsea, will be spending her Friday campaigning there, encouraging students and young people to vote.

But most importantly for Clinton, president Barack Obama will be campaigning in New Hampshire the day before the Nov. 8 election. Given what’s at stake, it makes perfect sense to deploy Clinton’s most popular and powerful surrogate in a state where voters can register up until the moment they cast their ballot.