Why this man is 2016 Republicans' favorite underdog

Who is Walt Havenstein and why are potential Republican presidential candidates flocking to stand by his side?

Helping his cause: he's the gubernatorial nominee in New Hampshire, running in the last statewide election before the 2016 presidential primary.

But Havenstein, a businessman, is a long shot, trailing Democratic Gov. Maggie Hassan by 10 points in the most recent poll, and is up against a governor who has history on her side: a first-term New Hampshire governor has not lost re-election in 88 years.

That fact hasn't stopped a cascade of Republicans from flying into the Granite State to offer their help - Republicans who in 2016 may need some help of their own mobilizing GOP primary voters in the state.

Topping the list, Gov. Chris Christie, R-New Jersey, has a ready-made excuse to be by Havenstein's side: Christie is the head of the Republican Governors Association, charged with electing GOPers across the country. Still, after so many visits - Friday will mark Christie's fourth trip to N.H. on Havenstein's behalf - it's easy to question his motives. When asked whether his June stop in the state had to do with his presidential ambitions, Christie feigned shock: "Absolutely not. How dare you."

Meanwhile, Christie is scheduled to head to the first-in-the-nation caucus state of Iowa for his third visit later this month on behalf of Gov. Terry Branstad.

Sen. Rand Paul, R-Kentucky, headlined a "unity breakfast" last month for the New Hampshire Republican Party's candidates, including Havenstein.

Havenstein has also had visits from Gov. Bobby Jindal, R-Louisiana; Rep. Mike Rogers, R-Michigan; and will campaign with Gov. Mike Pence, R-Indiana, later this month.

Gov. Rick Perry, R-Texas, scuttled his Havenstein visit Tuesday to deal with the growing concerns surrounding Ebola in his home state of Texas.

So, what effect do these heavy hitters have on Havenstein's chances on Election Day? Some say not much.

"How much real data is there that proves that one of these guys comes to New Hampshire to work hard to raise money? What they do is work really hard at promoting themselves," said Andrew Hemingway, who lost to Havenstein in the Republican primary last month. In a general election, "you need to be reaching outside of your own party to different folks, and these guys don't aid in that effort," he told CBS News.

Tom Rath, a former state attorney general who has been involved in state GOP politics for decades, disagrees. He believes the national attention from top Republicans assists with Havenstein's name recognition, boosts his profile, and reaches an important and substantial block of independent voters.

"Every time Chris Christie, Rand Paul or someone comes to New Hampshire to promote Walt, it helps drive a contrast between him and Gov. Hassan and what he is campaigning for," Rath told CBS News. "Folks can speculate on what it means for 2016 positioning but in 2014, these types of trips have real value."

Perhaps Rath is on to something.

While Havenstein is down 46-36 percent in Monday's UNH/WMUR poll, that's an improvement from the 17-point deficit he faced in the August UNH poll.

But regardless of how Havenstein fares on Election Day, his candidacy has provided ample opportunities for those potential presidential candidates to make a name for themselves in the crucial first-in-the-nation primary state.