As voters get ready to vote in the primary election, many of the candidates know already that they have been elected by default — a sad reflection on politics in Hawaii.

On the flip side, there are races in which the candidates who would seem to be the obvious choice are being challenged by others in their own parties — such as Joan Hood taking on Cynthia Thielen in the Republican primary for House District 50 (Kailua-Kaneohe).

Thielen is one of Hawaii’s most successful Republican legislators. First elected in 1990, Thielen in the last six years alone sponsored or co-sponsored more than 40 bills that became law.

That “Industrial Hemp Bill” that will allow the crop’s cultivation and distribution of its seed by multiple licensed local farmers? That was the result of years of effort by Thielen to establish another option for economic diversification in Hawaii. It was approved unanimously by both legislative chambers and signed into law on July 7.

Thielen also has been in the forefront of forward-thinking environmental initiatives, in particular advocating the use of wave-energy converters at Marine Corps Base Hawaii. She has supported allowing accessory dwelling units (ADUs) as a partial solution to the affordable housing crisis, and has been urging removing the general excise tax from purchases of locally produced food.

Thielen’s liberal streak is well known, but it’s not as if Hood’s GOP bona fides are much stronger — except, perhaps, in the religious conservative sense. She has been active in helping the homeless, and urges the usual GOP ideas about cutting wasteful spending, reducing regulations and offering tax breaks to stimulate business and employment.

But Thielen’s accomplishments are undeniable and her commitment to serving the constituents of her district outweigh any concern about her not being more predictably Republican.

Hood is to be applauded for her political engagement, but Republicans voting in this race should favor Thielen, who by winning would automatically be re-elected to the House, as no other candidates are competing here.

In other competitive House primaries outside the city core:

>> District 43 (Kalaleloa-Ko Olina-Maili): Karen Awana, a Democrat, is our choice to go up against Republican incumbent Andria Tupola, who won the seat from Awana in 2014.

Awana’s primary opponent is Stacelynn Eli, a manager for a home-improvement retailer, who also ran for this seat in 2014.

Awana was the representative of this district for eight years, and learned how to secure funding for various capital improvement projects and achieve incremental improvements in the area’s traffic and other problems. She has worked in the tourism industry for 10 years, and her community involvement has been extensive.

>> District 44 (Waianae-Makaha-Makua): This district has two contested primaries, with the incumbent in the Democratic race being Jo Jordan, appointed to the office in 2011. Her opponent is Cedric Gates, who ran for this same seat in 2014 as a Green Party candidate. Both he and Jordan are longtime residents of the district with extensive community ties, but we don’t see any reason at this time to replace Jordan as the Democratic standard bearer. On the Republican side, Marc Paaluhi gets our nod over Tamiko Sequin, a “wife, mother and educator” who has some concrete ideas about various issues, but lacks political experience of any sort. Paaluhi at least serves on the area neighborhood board, and his background in construction management could help in efforts to tackle housing and homelessness issues.

>> District 47 (Waialua- Kahuku-Waiahole): Two Republicans are seeking their party’s nomination in this race: Toagaifasa “Junior” Mataafa and the incumbent, Rep. Feki Pouha. Unfortunately, neither responded to repeated requests for information about their campaigns, so neither merits endorsement. The winner will face Democrat Sean Quinlan.

>> District 49 (Kaneohe-Maunawili-Kailua): Here’s another primary in which the candidate who deserves to be the party’s standard bearer is facing a challenge from within its own ranks. Democrat Ken Ito, the incumbent, has done a good job serving his constituents since 1995, often running unchallenged by candidates from other parties, including this year.

Ito’s opponent is Patrick Shea, a liberal Native Hawaiian attorney who has some good ideas about how to solve issues such as homelessness — but Ito’s practical streak makes him the preferred choice. The winner of this race gets into the Legislature.