What makes these N.H. voters so fickle?

Just two years ago, voters in New Hampshire’s First Congressional District chose Democrat Carol Shea-Porter over Republican Frank Guinta by a comfortable 8-point margin. They knew exactly who they were going to get. After all, Shea-Porter had represented the district in the past.

So what happened between 2012 and 2014 that made voters eager to toss Shea-Porter to the curb on election night — once again?

Political analysts in the state say it has less to do with anything she or Guinta did or said — and much more to do with the peculiarly well-balanced political makeup of the state’s eastern district. Unlike districts elsewhere that skew Republican or Democratic, the First District has become one of the most competitive in the country and, as a result, a bellwether for the national mood.

The district’s unpredictability is due to the “R+1” rating on the Cook Partisan Voting Index, which charts on a national map just how far left- or right-leaning a voting district is, said University of New Hampshire political science professor and longtime political analyst Dante Scala.

“That means the First District electorate votes 1 percentage point more Republican than the rest of the country does, and because you have a pretty well-balanced district — which includes strong Democratic areas like Manchester, Dover, and the Durham area, and towns in greater Manchester that are very Republican, like Bedford, Merrimack, Londonderry — it’s almost like a scale that’s perfectly balanced,” said Scala.

“That’s what keeps the district going back and forth. So if there is a national wave, it’s pretty easy to see why the district moves in one direction or the other,” he said.

Just how fickle are those First District voters?

This month’s election was the third go-round for Shea-Porter and Guinta. In 2006 Shea-Porter unseated incumbent Republican Jeb Bradley in an upset, and held the seat for two terms. In 2010, she lost to Guinta in a national Republican anti-incumbent sweep. In 2012, Shea-Porter won back the seat, beating Guinta 50 to 42 percent.

And this time around, Shea-Porter lost to Guinta again by about 3.5 points, or 8,740 votes.

In fact, the First District’s back-and-forth contributed to the mixed message sent by voters statewide this month: They elected one Republican and one Democrat to Congress. They elected Democrats for governor and US Senate — but turned control of the New Hampshire Legislature and Executive Council back to the GOP.

In the aftermath of her loss, Shea-Porter said mid-term elections “are always tough.”

But she also regrets not focusing more on independents, who account for 40 percent of the district’s registered voters.

“We know we need to get those independent voters. I don’t know what percentage of them showed up to vote, but when we are out there measuring Republican enthusiasm versus Democrat enthusiasm, we need to know that the independent voters hear our message, and are included when we talk to them,” said Shea-Porter.

She knew going in that the race could go either way — a matter of mid-term voter lethargy compounded by the district’s political mood swings.

And in a big Republican year, Shea-Porter just didn’t have the financial resources to compete, said Scala.

“Because the First District is so closely watched at the national level, the money is going to go where the Republicans think they can pick up a seat,” Scala said.

Shea-Porter acknowledges she couldn’t stand against the rush of what she calls “big money” that boosted her opponent as they neared the finish line — at a time when she had a slight lead in the polls. And she intends to become a vocal advocate, going forward, for campaign finance reform.

For their part, state Republicans describe Guinta’s latest victory as proof that the district was ready for a change. “I look forward to working with my colleagues in the 114th Congress to enact policies that strengthen the middle class, protect and preserve our entitlement programs while reducing our debt and deficit,” Guinta said after declaring victory.

Money aside, Wayne Lesperance, director of the Center for Civic Engagement and a professor of politics at New England College, said he doesn’t know if Shea-Porter could have done anything different this time around to win.

“In a midterm election where the president is unpopular, his party will suffer nationally. It’s just the zeitgeist. The mood of the electorate was tied to national issues people aren’t happy about,” Lesperance said.

Anyway, he’s more interested in what will happen in 2016, should Shea-Porter throw her hat back into the ring.

“There’s a very compelling case for Shea-Porter to run in 2016. Say Hillary Clinton wins the New Hampshire [presidential] primary. Now, you have Hillary here regularly stumping, boosting enthusiasm for Democrats, and a landscape more friendly for national races. Shea-Porter’s got absolutely nothing to lose – except for her time and money,” said Lesperance. “The only wild card is how voters in the First District will respond to a ‘four-peat’ between Guinta and Shea-Porter.”

Shea-Porter insists she’s not thinking that far ahead.

“Well, I don’t think Frank Guinta should run a fourth time,” she said, with a laugh. “And no matter what I decide to do next, I’m optimistic — I always am — that we’ll turn this around and the American public will ask the Legislature to change way they do business. I will keep talking about campaign finance reform at a national level, because clearly we need to do something about that.”