Maine and New Hampshire aren’t just neighbors. They might as well be siblings.

Both states have slightly more than 1.3 million residents, with similar demographics. Politically speaking, Pine Tree State and Granite State voters may tilt toward one party at any given time, yet they also pride themselves on their Yankee independence.

However, when it comes to attention from presidential candidates, the two states couldn’t be more dissimilar, despite the fact that each accounts for four Electoral College votes.

Always important in the primary race, New Hampshire in 2012 already has been labeled as a key “swing state” likely to draw major attention from President Barack Obama and his GOP challenger, Mitt Romney. As for Maine, well …

“New Hampshire has shown a propensity to turn on a dime. Maine has not,” said Larry Sabato, director of the University of Virginia Center for Politics and co-producer of its popular “Crystal Ball” election forecasting.

Mainers are, by now, probably accustomed to their role as just another spectator to the presidential political frenzy across the border (and many would likely say they are content to keep it that way).

However, as the nation barrels head-on into what is expected to be another close race for the White House, it is worth asking a simple question: Is Maine relevant in 2012? If not right now, can it be by November?

Ask the Obama and Romney campaigns and you will, of course, get the same answer: Yes, Maine is important, given the potential for a squeaker of a race.

Several factors in play this year — combined with a vote-counting process that makes Maine unique — truly could give the Pine Tree State a somewhat larger role in 2012.

Public opinion polls, including one commissioned by The Portland Press Herald in late June, show Obama leading Romney among Maine voters.

The first reason that Maine could rise to something more than a simple afterthought in this year’s election is an often-overlooked quirk in the state’s election process.

Maine is one of two states — Nebraska being the other — where the presidential vote is not necessarily winner-take-all. The Pine Tree State contributes four electors to the Electoral College, which actually determines who wins the presidency.

Unlike in 48 states, Maine can split its electors if the majority of voters in each separate congressional district support different candidates. So if Obama picked up the majority of voters in the 1st District and Romney won the 2nd, each candidate would receive one elector. Whoever wins the total statewide vote then would pick up the two at-large electors, resulting in a 3-1 split.

While such a scenario never has played out in the 40 years since the policy has been in place in Maine, Nebraska had its first split vote in 2008. Conditions could be ripe for it to happen here this year because of the 2nd District’s more conservative bent and the potential for the most competitive congressional race there in years.

“Obama would certainly be favored in the 2nd Congressional District, but I think Romney has a chance there,” said longtime election watcher and political science professor Jim Melcher, at the University of Maine at Farmington. “A lot of the national reports don’t remember that Maine can split its electoral vote by congressional district, so they tend to just lump the whole state in under Obama. I think he is going to carry the state, but I think the 2nd District is at least potentially competitive.”

Party leaders are certainly aware of the possibility for a split, although they not surprisingly disagree about who would walk away with three electors and who would get one in such a situation.

“I believe it is a perfect storm,” said Charlie Webster, chairman of the Maine Republican Party. “I think (Obama) will lose the 2nd District, and I think he will lose the 2nd District by enough of a margin that we could win three of the four (electors).”

“There is no chance that is going to happen,” countered Webster’s counterpart, Maine Democratic Party Chairman Ben Grant. “It’s really one vote that is in contention.”

Maine’s 2nd District, which encompasses most of the state and many of the more rural areas, definitely has a more conservative lean than its neighbor to the south. Fifteen of the state senators representing the district in Augusta right now are Republicans, and in 2008 Piscataquis County was the only county in all of New England where McCain beat Obama at the polls.

This year, the race for the 2nd District seat itself is in the GOP’s sights.

Last week, the GOP’s national campaign arm for House races, the National Republican Campaign Committee, named Kevin Raye to the list of 28 “young guns” across the country who the committee believes are top contenders.

That designation means that Raye, a Perry resident who is the state Senate president, can expect to receive considerable financial help from the NRCC and other Republican groups, probably in the form of television and media ads. It’s a sure bet that many of those ads will try to link incumbent Democratic Rep. Mike Michaud with Obama, who probably is less popular in the district’s vast rural areas.

Nathaniel Sillin, regional spokesman for the NRCC, called Maine’s 2nd District “one of our top races in the country” this past week. In the eyes of the NRCC, the presidential and congressional elections are linked.

“The Romney campaign is going to have a focus there,” Sillin said, adding that it should help with the get-out-the-vote effort, and that could benefit Raye.

“A lot of it will depend on the Kevin Raye campaign,” said Sandy Maisel, professor of government at Colby College. “If Kevin Raye’s campaign is considered a serious challenge to Michaud, then there might be some coattails for (Romney) to ride on.”

The 1st District race between Democratic incumbent U.S. Rep. Chellie Pingree and Republican Jonathan Courtney, the majority leader in the state Senate, is currently viewed as less competitive, although Republicans are hoping to close the gap there as well.

National campaigns also consider how much proverbial bang for their buck they can get by buying TV airtime for ads in that district relative to other districts. Maine’s 2nd District happens to be in an exceptionally cheap and easy media market.

In other words, buying 30 seconds of airtime at TV stations in, say, Bangor or Presque Isle is much cheaper than airtime in mega-media markets elsewhere. So the Romney and Obama campaigns may calculate that the relatively low investment is worth the opportunity to snag even just one electoral vote.

Sabato, at the Center for Politics, said any concerted effort by the campaigns probably wouldn’t start until mid-October, and then only if September polls indicate a close race in the 2nd District.

There’s always the potential that some of the so-called super-PACs that are flush with money will be looking for a new market in which to run independent ads for or against one of the candidates, Sabato said; but he is skeptical that Romney can capture any electors.

“Maine has never done it,” Sabato said of the split. “Of course, until 2008, Nebraska had never done it, either. Is it possible? Yes. Is it probable? No.”

Even if Maine is not in contention in the fall, however, television viewers in the southern part of the state probably will get their fill in campaign advertising on the presidential election. That’s because many New Hampshire residents receive Portland stations’ transmissions.

“Since Maine is a relatively inexpensive media buy, they can reach voters in New Hampshire,” Melcher said, “and I think New Hampshire is going to be one of the most contested states.”