State Sen. Ron Menor, D-17th (Mililani, Waipi'o), is locked in a pitched election battle against city official Michelle Kidani, while in a surprising House race Rep. Rida Cabanilla, D-42nd (Waipahu, 'Ewa), was trailing narrowly to political unknown Mike Schultz in her bid for re-election, according to early returns.

In another tight Central O'ahu legislative race, Sen. Clarence Nishihara, D-18th (Waipahu, Pearl City) was holding off a challenge from Rep. Alex Sonson, D-35th (Waipahu, Crestview) in early returns.

State Rep. Josh Green, D-6th (Kailua, Keauhou) was ahead of former councilwoman and representative Virginia Isbell in a winner-take-all Democratic shootout to replace Paul Whalen for the 3rd Senate District (Kohala, Kona, Ka'u) seat.

In closely watched House races:

• Union official Mark Nakashima was leading three other Democrats in the 1st District (Hamakua, North Kohala) while council aide Steven Offenbaker was ahead of Eric Weinert on the Republican side.

• Waipahu Community Association official Henry Aquino appeared on his way to winning the Democratic primary for the 35th District (Waipahu, Crestview) seat to replace Sonson. The winner will face Republican Steven Antonio, who ran unopposed in the primary.

• In the 51st House District (Waimanalo, Lanikai) where incumbent Democrat Tommy Waters chose not to run for re-election, Democratic newcomer Chris Lee was running ahead of two others in a fight to decide who will go up against Republican and former Rep. Quentin Kawananakoa in November.

• In the 24th House District (Manoa), where Kirk Caldwell left in an aborted attempt to run for the Honolulu City Council, Democrat Isaac Choy and Republican Jeri Jeffryes faced no opposition in the primary and will face off in the general.

All 51 House seats, being two-year jobs, are up for grabs tonight, while 12 of 25 of the four-year Senate seats are at stake.

Two Senate Democrats seeking re-election had no opposition and were automatically sent back: David Ige, D-16th (Pearl City, 'Aiea) and Robert Bunda, D-22nd (N. Shore, Wahiawa).

Twenty Democrats and two Republican incumbents to the House also won re-election: Jerry Chang, D-2nd (Hilo); Robert Herkes, D-5th (Ka'u, S. Kona), Mele Carroll, D-13th (E. Maui, Moloka'i, Lana'i); Hermina Morita, D-14th (Hanalei, Anahola, Kapa'a); James Tokioka, D-15th (Lihu'e); Roland Sagum III, D-16th (Ni'ihau, Lehua, Waimea); Lyla Berg, D-18th (Kuli'ou'ou, Niu Valley, 'Aina Haina); Scott Nishimoto, D-21st (Kaimuki, Kapahulu, Diamond Head); Scott Saiki, D-22nd (Moili'ili, McCully, Kaimuki); Della Au Belatti, D-25th (Makiki, Tantalus); Sylvia Luke, D-26th (Punchbowl, Nu'uanu); Karl Rhoads, D-28th (Downtown, Makiki); John Mizuno, D-30th (Moanalua, Kalihi Valley); Glenn Wakai, D-31st (Salt Lake, Tripler); Lynn Finnegan, R-32nd (Aliamanu, Airport); Blake Oshiro, D-33rd ('Aiea, Pearlridge); K. Mark Takai, D-34th (Pearl City, Newtown); Ryan Yamane, D-37th (Mililani, Waipi'o); Marcus Oshiro, D-39th (Wahiawa); Ken Ito, D-48th (Kane'ohe); Pono Chong, D-49th (Kane'ohe, Enchanted Lake) and Cynthia Thielen, R-50th (Kailua, Mokapu).

Currently, the Democrats hold a 44-7 advantage over the Republicans in the House of Representatives while they have a 21-4 majority in the Senate.

Reach Gordon Y.K. Pang at gpang@honoluluadvertiser.com or 690-8908.