Let’s get real. The population of the entire state of New Hampshire is less than that of the city of San Antonio, Texas. Yet the 2012 GOP presidential nomination may be decided in the Granite State, where the campaigns are focused on back-to-back debates this weekend. The stakes are huge, and these debates may mean more than any of 18 preceding events held this campaign season.

Here’s why.

New Hampshire pays attention. They take their politics even more seriously than Iowa. Virtually every New Hampshire voter will be watching the debates, and upwards of 50 percent are likely to participate in the “first in the nation” primary, scheduled this year on Jan. 10.

New Hampshire loves to be contrarian and rarely follows the conventional wisdom. And the situation there can change quickly. In 2008, Barack Obama went into New Hampshire with a 15-point lead, but days later he was stomped by Hillary Clinton. In 2000, the prohibitive favorite George W. Bush, who won Iowa, got crushed by John McCain by 19 points. And Ronald Reagan turned things around in New Hampshire in 1980 after losing to George H. W. Bush in Iowa.

Yet it’s not always about who wins, but who defies expectations. Bill Clinton was crowned as the “Comeback Kid” when, after finishing a distant third in Iowa in 1992, and trailing in the polls, he came within single digits of the winner in New Hampshire.

Independent-minded New Hampshire voters don’t much like establishment elites and respond more to gritty blue-collar types, which is why Pat Buchanan did well in 1996.

So, the New Hampshire debates Saturday night in Manchester and Sunday morning in Concord will be critical. While the press is fixated on how the “not-Mitt Romneys” will attack the real Mitt Romney, that’s not what’s going to be important or what will move numbers. There’s not much any other candidate can say about Romney that New Hampshire voters haven’t already heard. And they know Newt Gingrich is nothing more than a jilted lover at this point, so they will discount his broadsides.

The key will be the extent to which Rick Santorum, who lost to Romney in the Iowa caucus by just a handful of votes, comes off as authentic. He has a very real blue-collar background and story. Even if some of his more conservative positions may seem extreme, unlike Romney, Santorum has been fiercely consistent over the years. And there is a compassion to his conservatism as he talks about how policies affect families and how families affect society.

The challenge for Santorum is that he is not a Washington “outsider.” He has spent decades in D.C., both as a politician and a lobbyist, and has a long history of defending big government, including, and especially, earmarks.

So, at Saturday night’s fight and Sunday morning’s brawl, ignore the attacks on Romney. Look to see how effectively Santorum deflects the slings and arrows directed at him, and whether or not he comes off as genuine.

And if it’s not Santorum’s turn to shine, it may well be Jon Huntsman’s. He has staked his entire campaign on the outcome of this pivotal primary, where undeclared voters can pull the lever as either Republicans or Democrats.

The New Hampshire debates are going to be all about who can make it real.