Riding the strength of President Obama’s re-election, the Democrats strengthened their dominance at the state Legislature, picking up one seat in the House while maintaining their 24-1 stronghold in the Senate.

Three incumbents — Democrat Rep. Marilyn Lee and Republican Reps. George Fontaine and Corinne Ching — lost their bids for re-election Tuesday, ousted by relative newcomers.

The net gain of one in the House for the Democrats, who hold a 44-to-7 edge in that chamber, was largely attributed to one factor.

“All the Democrats were on the coattails of you know who — President Obama,” said House Speaker Calvin Say, who fended off two challengers to win re-election.

In two of the more high-profile Senate races, two Democrats — Sen. Clayton Hee and Laura Thielen, a former Cabinet member under Republican Gov. Linda Lingle — beat their Republican challengers.

Hee, 59, who heads the powerful Senate Judiciary Committee, topped his Republican opponent, former House member Colleen Meyer, 73, by more than 800 votes, capturing 53.4 percent of the total in the 23rd District covering Heeia, Laie and Waialua.

In the 25th District spanning Hawaii Kai, Waimanalo and Kailua, Thielen, 51, who served under Lingle but caused a stir when she signed up to run as a Democrat, defeated former Sen. Fred Hemmings, 66. Thielen tallied 59.5 percent of the vote.

Lee, 72, the only Democrat incumbent to lose, was bested by Beth Fukumoto, 29, research director for House Republicans, in the fight to represent Mililani’s District 36. Fukumoto picked up 52.3 percent of the vote.

Fontaine, 52, lost to Democrat Kaniela Ing, 23, a former legislative aide, in South Maui’s District 11, while Ching, 51, was beat by Takashi Ohno, 28, an elementary school teacher, in District 27, which includes Nuuanu, Liliha and Alewa Heights.

In two of the closest races in the House, Republican Bob McDermott, a former House member, beat his Democrat challenger, Chris Kalani Manabat, by 138 votes in District 40’s Ewa Beach and Iroquois Point, while Republican Lauren Cheape, a former Miss Hawaii, bested her Democratic opponent Jake Bradshaw by 67 votes in District 45, which includes Mililani, Schofield and Kunia.

McDermott, 49, is executive director of the Honolulu Council of the Navy League. Manabat, 28, was a first-time candidate and office manager for his mother, Rep. Rida Cabanilla.

Cheape, 25, who worked on her family’s Wahiawa farm, and Bradshaw, 32, a small business owner, were first-time candidates.

In one of the more closely watched House races, Say, 60, who has served in that chamber since 1976, fended off Republican Julia E. Allen, 64, and Green Party candidate Keiko Bonk, 58, in the battle to represent the 20th district, which includes Palolo, St. Louis Heights and Kaimuki.

Say, a self-employed businessman, has been House speaker for 13 years, the longest reign for that position in state history.

Bonk, a former Hawaii County Council member, was heavily backed by the local hotel workers union and the Sierra Club.

Because of reapportionment, all 76 seats in the Legislature technically were up for grabs.

But because 28 candidates had no general election opponents, nine in the 25-member Senate and 19 in the 51-member House won their seats outright in the August primary.

The fight for the right to represent the reconfigured 23rd District in the Senate pitted two veteran politicians with relatively high name recognition.

Hee, a former public school teacher, has been in the Legislature for the past 10 years. Meyer, his rival, served in the House for about 14 years until November 2008, when she lost her re-election bid.

Meyer, regarded as a conservative, was hoping to benefit from stong turnout by Mormons in Laie for Republican Mitt Romney in the presidential race. Romney is a member of the Church of Jesus Christ of Latter-day Saints. Meyer is Catholic.

Hee and Meyer gave voters clearly different choices on some key issues.

Hee, for instance, actively opposed the development of the planned Ho‘opili and Koa Ridge housing developments on Oahu. Meyer favored them.

In the Senate battle for District 25, Thielen, Department of Land and Natural Resources director under Lingle and daughter of Republican state Rep. Cynthia Thielen, won the August primary by beating incumbent Sen. Pohai Ryan despite defying her party’s leadership.

Party leaders argued that Thielen was ineligible to run as a Democrat because she had not been a member in good standing for the six months required by party rules. But Thielen ran anyway.

Former Sen. Hemmings, her opponent, was attempting to reclaim the seat he left in 2010.

In the House, the leadership of that chamber potentially was at stake in the race for the 20th District seat.

In the House District 47, which includes Waialua, Kahuku and Waiahole, Republican Richard Fale beat Democrat Ululani Beirne, a former legislator, garnering 54 percent of the vote.