Why Jeb Bush Sees Himself as the John McCain of 2016

MANCHESTER, N.H. -- As polls show Republican presidential candidate Jeb Bush slipping, and though his donors may be worried, he's certainly not, at least visibly.

Speaking to ABC News today, Bush offered an anecdote about a previous GOP candidate whose chances seemed slim.

"This time, eight years ago, John McCain was traveling through the Atlanta airport. I saw him and he had no aide, no person, [he was] by himself because his campaign was supposed to be ended," Bush said of the Arizona senator. "He won the Republican primary that year. This is how the process works; you have to go earn it."

While Bush's events are well-attended, they are no match for the likes of fellow candidates Donald Trump and Ben Carson, who have seen their stadium events packed with thousands of people.

"It doesn't frustrate me at all," Bush said. "Because I know at the end, the people I'm talking to and listening to are going to be the ones who will decide who the nominee will be and I believe I will be that person."

Not oblivious to the polls, however, his campaign has started to ramp up its advertising efforts. Here in New Hampshire, they've dropped a whopping $4.6 million for ads slated to air in January and February.

Between New Hampshire and other early primary states -- Iowa and South Carolina -- campaign officials are spending close to $8 million on ads, in the hopes it will bolster their on-the-ground efforts.

Today, Bush portrayed no uneasiness, instead simply steadfast in the belief that polls, at this early stage, mean nothing. He says he's prepared for the many months ahead.

"It's a long haul, man," he said. "A long haul."