With less than 48 hours until the New Hampshire primary, Republican candidates are criss-crossing the state to woo the GOP base, just as Hillary Clinton and Bernie Sanders cozy up to loyal Democrats.

But all 10 candidates know that the most important – and unpredictable – voters are the Granite State’s incomparable “undeclared” electorate – the independents.

Independent voters remain at the heart of New Hampshire’s independent streak, a state known for its mercurial demeanor. This year, independents will likely play a bigger role in the first-in-the-nation primary’s outcome than ever – and that prospect is giving pollsters fits.

The swing state’s undeclared voters, who can cast ballots in either party’s primary, have reached an unprecedented 44 percent of the overall electorate – more than the Republicans or the Democrats. Half of the voters under 40 are registered as undeclared to either party.

For months, political reporters on the ground in New Hampshire have detailed the influence of the independents.

“There is no doubt that the independent voters will decide this New Hampshire primary, and I think that campaigns are just beginning to figure out what message they can best use to reach out to them,” said Mike Dennehy, the Republican consultant who played a key role in John McCain’s New Hampshire primary wins in 2000 and 2008. “It is becoming increasingly clear that a 5-point win among this group could decide who the winner will be.”

Some predict that as many as 90,000 of the expected 250,000 Republican primary voters will bear the independent mantle as the undeclared voters gravitate toward the more volatile GOP contest.

In a recent report, the New York Times described the New Hampshire playing field this way:

There are few titles in American democracy as privileged as “undeclared New Hampshire voter.”

Presidential candidates obsess over them. Operatives tailor advertisements to their whims. And in an election season more volatile than any campaign is likely to have imagined, the state’s electoral free agents here are … (grappling) with how to exercise their unusual power to control the fates of candidates in either party.

The candidate who has focused on the independent vote more than any other is Ohio Gov. John Kasich.

He’s following the blueprint of John McCain, who won the state in 2000 on the strength of his appeal to independents. That upset victory over George W. Bush came as McCain completed 100 town hall meetings with voters. Similarly, Kasich hit the 100-town-hall mark on Friday. The strategist who engineered McCain’s surprise win 16 years ago was John Weaver, who is running Kasich’s campaign.

On Tuesday, Kasich has little chance of surpassing the rest of the GOP field, especially Donald Trump, who leads in every poll. But Kasich quietly has presented himself as the anti-Trump.

“He just sounds reasonable,” said one voter. “Not crazy, like the others.”