Elsewhere in New England, Republicans lost every major election for Congress and governor. The six-state region will not have a single Republican U.S. House member, and only two Republican senators will serve in the next session. Only one of six governor's offices will be filled by a Republican.
The results come in an election when local candidates were hurt by national Republicans seen as extremists by the region's moderate and independent-minded populace, and in a year when Democrats turned out in big numbers to re-elect President Barack Obama. The losses disheartened Republicans, who have been fighting dwindling numbers here for years.
"It's a nightmare," former Republican U.S. Rep. Chris Shays, of Connecticut, said a day after the election.
Rob Coupe, political director for Rhode Island Republican congressional candidate Brendan Doherty, seen as the party's best shot in two decades to pick up a House seat for the state, struggled when asked to explain his candidate's defeat. Doherty came in a stunning 12 points behind freshman Democratic Rep. David Cicilline.
"I think it's just tough to be Republican in Rhode Island," Coupe said. "I don't know what else to say."
The rout extended to local races, as well. Republicans fell from eight to five out of 38 seats in the Rhode Island Senate, leading one Republican operative to observe on Twitter, "RI Senate GOP can caucus in a mid-size sedan. How convenient." The same can be said in Massachusetts, where only four of 40 state senators are Republican.
Massachusetts has produced Democratic icons like the Kennedys and the late House Speaker Tip O'Neill, and the region is known for liberal stances on issues like gay marriage, which is now legal in all New England states except Rhode Island. But the area once had a number of "rock-ribbed" Republicans who stood for fiscal conservatism, environmental stewardship, and protection of personal liberties, including support of abortion rights. As the national party has moved further right and focused on social issues, it has turned off voters and candidates alike.
Lincoln Chafee — whose father, the late Sen. John Chafee, defined the Republican brand in Rhode Island for decades — lost his Senate seat in 2006 and became an independent in 2007. He spoke at the Democratic National Convention to support Obama this year.
Maine still has a Republican governor, tea party-backed Paul LePage, and Connecticut, Rhode Island and Vermont had Republican governors who left office in January 2011. But the overall trend has been Republicans losing ground, even in New Hampshire and Maine, once strongholds for the party.
In New Hampshire, the "live free or die" state that has long prided itself on low taxes and small government, Republicans lost both the state's U.S. House seats, as well as control of the state House of Representatives, although they retained narrow control in the state Senate. Maggie Hassan, a Democrat, won the governor's office.
Maine still has a sitting Republican U.S. senator, Susan Collins. But Democrats on Tuesday won both chambers of the Legislature, and independent former Gov. Angus King won the U.S. Senate seat being vacated by centrist Republican Olympia Snowe.
The only other Republican who represents the region in Washington is Sen. Kelly Ayotte, of New Hampshire. Vermont's senators are a Democrat and an independent, Bernie Sanders, who calls himself a democratic socialist and caucuses with Democrats.
Shays, a moderate who lost his congressional seat to a Democrat four years ago, ran for Senate this year and lost in the primary to Republican Linda McMahon. McMahon lost to Democratic Rep. Chris Murphy on Tuesday.
"My party is out of touch, and the brand is not a good brand," Shays said, then ticked off a list of problems, including Senate candidates in Missouri and Indiana who made comments about rape that many voters here found offensive. The national party can't cater just to voters from places like Oklahoma, he said.
"We're New England Yankees, and we think a little differently," Shays said. "The people we represent focus more not on ideology, but on common sense."
While much of the region has voted heavily Democratic in recent years, voter registration numbers show a more nuanced picture. Voters unaffiliated with any party outnumber Democrats and Republicans in all the New England states that collect that information, representing 40 to nearly 53 percent of the electorate, depending on the state. Registered Democrats outnumber registered Republicans everywhere but New Hampshire. Only Vermont doesn't track such information.
To appeal to independents, Brown positioned himself as a moderate, pro-abortion rights Republican and one of the most bipartisan members of the Senate. He ran TV ads that pictured himself with Obama, while barely uttering Romney's name. It didn't work. He lost by 8 points to Warren.
"They were able to label him and convince enough voters that he would be the 51st vote in the Senate to reverse successes that women had made over the years," said Gene Hartigan, a Republican consultant and former state party director.
Rhode Island congressional candidate Doherty argued the state would be better served by having a Republican in the GOP-controlled House, and said he could exert his influence to moderate the national party's positions.
Voter Lisa Harden, of East Providence, R.I., didn't buy it.
"He's a Republican, and he's going to follow the other Republicans," she said Tuesday after casting a ballot for the Democrat.
Across New England, national Republican groups spent millions in vain to get rid of Democratic members of Congress. In Massachusetts, which hadn't sent a Republican to the House since 1994, they had banked on Richard Tisei ousting U.S. Rep. John Tierney, a veteran Democrat who had been tarnished by fallout from a gambling scandal involving his wife's family.
During the campaign, Tierney suggested his opponent would back a far-right agenda in the House. Tisei, a former state senator who is openly gay, ran as a moderate yet lost narrowly.
Republicans blew it after 2010, when several tea party-backed candidates swept into Congress, and then focused on issues that turn off New England voters, said Robby Mook, executive director of the Democratic Congressional Campaign Committee.
"They're not interested in passing fringe legislation about abortion, individual health care decisions," said Mook, a Vermont native. "They support civil liberties."
Hartigan said Republicans must acknowledge the growing political clout of women, young people and minorities and adjust their platform on social issues if they are to regain an edge, a sentiment echoed by Shays.
Darrell West, director of governance studies at the Brookings Institution think tank, said the national party has no incentive to care about New England because population has shifted to the South and West, and that's where the party sees its future.
Local Republicans are "going to have to get used to it, because it's hard to see this changing anytime soon," West said.
But some in the party took a more optimistic view.
"The major problems of the day, our crushing debt and bad economy, were not fixed by this election, and these problems will re-emerge bigger than ever," said Jerry Labriola Jr., chairman of the Connecticut GOP. "It's inevitable that the voters will need to turn to pro-growth, common-sense solutions offered by Republicans."
Salsberg reported from Boston. Contributing were Associated Press writers Sue Haigh in Hartford, Conn., Norma Love in Concord, N.H., and David Sharp in Portland, Maine.
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