The Republican Party broadened its hold on governorships to 30 states on Tuesday, with a takeover of North Carolina’s chief executive post.

Democrats were on the defensive this year as they struggled to hold onto governors’ seats in conservative-leaning states where President Obama’s popularity has dipped. This left them vulnerable in North Carolina and Montana and made it difficult for them to gain traction in Indiana.

At the outset of the election cycle, Republicans pledged to reclaim several chief executive posts, but Democrats defended themselves in a handful of states that were tossups or leaned Republican.

Eleven governorships were up for grabs this year. Coming into the election, Republicans held 29 seats, and Democrats had 20. One was occupied by an independent.

The GOP not only became the first political party in a dozen years to capture at least 30 governor’s offices; its victories Tuesday mean that no Republican governor has lost a general-election campaign in five years. Republicans could pick up two more governorships if they win in Montana and Washington state, where polls have shown tight races.

Republican Governors Association Chairman Robert F. McDonnell, Virginia’s governor, said in a statement that Tuesday’s victories put his party in a position to make further political gains: “There’s no doubt that the Republican Party’s strength comes from the states, and the RGA’s ability to expand our majority provides optimism for the future.”

Democrats held onto the governor’s mansion in New Hampshire’s open-seat race Tuesday. Former state Senate majority leader Maggie Hassan beat GOP lawyer Ovide Lamontagne in the contest to replace Democratic Gov. John Lynch. Democrats put $8 million into the gubernatorial race, outspending Republicans there.

Martin O’Malley, the Democratic Governors Association chairman and Maryland’s chief executive, said that Hassan will “stand up to the Tea Party legislature’s wrong-headed priorities that will only take New Hampshire backwards.”

While Hassan and Lamontagne embraced fiscal conservatism — they both pledged to veto a personal income or general sales tax — Hassan emerged as a vocal proponent of abortion rights and gay rights. She vowed to veto legislation that would repeal the state’s same-sex marriage law or curb the abortion, birth control and health services provided by Planned Parenthood of Northern New England.

Democrats retained a couple of governorships that had once been considered vulnerable. West Virginia’s Earl Ray Tomblin beat back his GOP challenger — businessman Bill Maloney, whom he narrowly edged out in a 2011 special election — to win reelection, as did Jay Nixon in Missouri. Nixon beat businessman Dave Spence.

But in two more open-seat races, Democrats faced risks. In Montana, Republican former congressman Rick Hill was locked in a tight contest with state Attorney General Steve Bullock (D) to replace term-limited Democratic Gov. Brian Schweitzer. GOP presidential nominee Mitt Romney was running well ahead of Obama there, and Bullock would have to overcome the state’s heavy Republican tilt to emerge victorious.

Republicans picked up their first win Tuesday night in North Carolina, where unpopular Gov. Beverly Purdue (D) didn’t run for reelection. Former Charlotte mayor Pat McCrory became the first Republican to win the governorship since 1988 when he defeated Lt. Gov. Walter Dalton, a Democrat. Obama’s win in North Carolina in 2008 helped usher Purdue into office, and the state remains a presidential battleground, but Obama’s candidacy did not provide the same lift it delivered four years ago.

McDonnell, whose group poured $5 million into the race, issued a statement saying that with McCrory’s win, “North Carolina residents can look forward to four years of balanced budgets, limited taxes and economic growth.”

In Washington state, Democratic former congressman Jay Inslee, who served 13 years in the House before resigning his seat to focus on the race, is battling state’s Attorney General Rob McKenna. Inslee, who lives in the Seattle suburb of Bainbridge Island, is an outspoken advocate for tackling climate change and promoting renewable energy. But McKenna, who has won twice statewide, has made a strong appeal to independents who might want to split their tickets even as they support Obama’s reelection bid. If McKenna wins, he would be the first Republican governor since 1980.

In Indiana, U.S. Rep. Mike Pence (R) won the governorship over Democrat John Gregg, a former state House speaker, despite the fact that controversy surrounding the state’s failed GOP Senate candidate, Richard Mourdock, made the race more competitive. Gregg tried to link Pence, who had chaired the House Republican Conference and championed conservative causes since coming to Washington in 2001, to Mourdock’s remarks suggesting that any pregnancy arising from rape is something “God intended.”

Two Republican governors in conservative states — North Dakota’s Jack Dalrymple and Utah’s Gary R. Herbert — won reelection Tuesday. Democratic incumbents held on to their seats in Delaware, with a victory by Jack Markell, and in Vermont, where Peter Shumlin won.