Top Republican strategists are increasingly worried that a 2012 ticket led by former Speaker Newt Gingrich (Ga.) — instead of former Massachusetts Gov. Mitt Romney — could hurt the party downballot, especially in the Northeast.

The region is expected to be a top battleground in the fight for control of Congress. Although redistricting has shifted many lines, in 2010 Republicans won 61 House districts that were carried by Barack Obama in 2008.

Last year the GOP picked up 14 seats across four states: New York, New Jersey, New Hampshire and Pennsylvania. Many of those freshmen will have tough races next year in those Democratic-leaning states and need help from the top of their ticket.

As the nomination fight between Romney and Gingrich heats up, the electability argument — including which man is better positioned to help downballot candidates — will become a frequent talking point for the frontrunners’ surrogates.

“It will make it a lot more difficult for a lot of candidates in New England if Mitt Romney is not the nominee,” said Brad Card, a Republican lobbyist in Washington, D.C., and Romney supporter.

Unaffiliated strategists also argued Romney would be beneficial to candidates in blue and purple states.

Mike DuHaime, a New Jersey Republican strategist who ran the National Republican Senatorial Committee’s independent expenditure effort in 2010, said key blocks of independent voters across the Northeast would likely have an easier time voting for Romney than other potential GOP contenders. He explained independents won’t have the “knee-jerk opposition” they might have to a candidate from a different part of the country.

“Having somebody from the region will give some independent voters some comfort that they haven’t had with the Republican Party since the late ’80s,” he said, noting that could help downballot GOP candidates.

Former Rep. Tom Davis (R-Va.) said the jury is still out on who might help downballot candidates nationwide because “people are in the mood for a change [so] it’s not going to matter a whole lot” who is on the top of the ticket.

But Davis, who served as chairman of the National Republican Congressional Committee a decade ago, said the Northeast was a different story.

“I think Romney’s going to be a better candidate in the Northeast, certainly in New England and New York,” he said.

The crux of GOP operatives’ concern about Gingrich as the nominee is the former Speaker’s unpredictability. Specifically, his penchant for off-message ideas could distract from a wider strategy of hammering Obama on the lousy economy.

In the 1998 and 2000 elections, Democrats effectively hammered Republicans in New York for real or perceived connections to Gingrich and painted the GOP as the “Party of Newt.” Empire State Republicans don’t want to see a repeat of that in 2012.

“There’s a fear of Newt Gingrich being the nominee for people in New York,” said a plugged-in Republican strategist in the state. “And not just a fear of ‘anyone but Romney,’ but Newt Gingrich is problematic above and beyond that,” the source said, noting the former Speaker’s “negatives.”

North of the Empire State, the apprehension about Gingrich as the nominee is no less intense in the wake of his ascension as the presidential frontrunner after his campaign was written off earlier this year.

Former Rep. Christopher Shays, who served with Gingrich for years but has endorsed Romney, is running an uphill battle to succeed Sen. Joe Lieberman (I) in Connecticut. In an interview, the Republican praised Gingrich for change he brought to Washington, D.C., but said it came with a political cost.

“The problem is, because Newt tried to bring so much change to Washington, and because of his flaws, he would have mixed results in some states. He wouldn’t run as well in Connecticut because some people are afraid of him, some people dislike him and some people, who are partisans, resent the fact that he actually got the Republicans to stick their head above the ground,” Shays said.

In Massachusetts, where Sen. Scott Brown (R) faces a tough re-election fight, having the former governor at the top of the ticket could help. One poll taken this month showed Romney with a 40 percent favorable rating in Massachusetts. Just 22 percent of Bay Staters had a favorable view of Gingrich.

In New Hampshire, Republican Reps. Frank Guinta and Charles Bass face tough races and will need all the help they can get. Romney has all but become a Granite State resident — he owns a home on Lake Winnipesaukee and has been campaigning there for many years. For a number of reasons, New Hampshire Republicans see Romney as the nominee who is best-positioned to help their vulnerable Members.

“If he’s head-to-head with Obama, he’s really going to pull the ticket up” in New Hampshire, one unaligned Granite State Republican strategist told Roll Call.

Jamie Burnett, an unaligned New Hampshire GOP consultant, concurred.

“His strength here — and what would make him a strong top of the ticket here — has more to do with the fact that he ran a competitive race here four years ago … and he has a large, dedicated organization in the state,” he said.

If New Hampshire, which Obama won with 54 percent in 2008, becomes a true tossup state, the rest of the GOP ticket will be buoyed.

Bass, who has endorsed Romney, said the former governor has the best chance of carrying New Hampshire.

“If our nominee … carries the state, that’s going to be good for all of the candidates down the line, including me,” Bass said. “I would suggest that Newt Gingrich is much more of an unknown.”

An email to a Gingrich spokesman seeking comment was not returned.

Part of the Republican concern is rooted in Gingrich’s decades of history in D.C. “Is Newt viewed by independents as a creature of the past?” wondered influential GOP strategist Brad Todd. “To this point, Obama’s saving grace always is he is a candidate who looks and sounds and talks like America’s future.”

Todd said that Gingrich, who has been in the political arena for so long, “may have a hard time in competing with Obama in the parts of the campaign that talk about the future.”

Perhaps the biggest fear of all among Republicans is that Gingrich rips GOP messaging away from Obama and the economy and toward him.

“You could be planning and working the best campaign with lots of good ammunition,” the plugged-in New York GOP strategist said. “And then instead of standing there at a press conference answering questions about the economy or jobs or the failed stimulus plan, you’re out there trying to duck questions about Newt.”