Josh Green, Hawaii’s second-in-command, wins the Democratic primary for governor.

Lt. Gov. Josh Green of Hawaii won the Democratic primary for governor, according to The Associated Press, putting himself in a strong position to secure the top office in a reliably blue state.

Mr. Green defeated six other Democrats, including Representative Kai Kahele and Vicky Cayetano, a former first lady of Hawaii. He will face the Republican nominee, Duke Aiona, in November; the winner then will succeed Gov. David Ige, a Democrat who cannot run for re-election because of term limits.

Mr. Green, 52, a former state legislator and an emergency room doctor, was elected lieutenant governor in 2018. Initially, he focused on combating homelessness. But his medical background became an asset when the pandemic began and Mr. Ige named him the state’s coronavirus liaison.

As vaccines were becoming widely available in the spring of 2021, a poll conducted by two Hawaii news organizations, Honolulu Civil Beat and Hawaii News Now, found that Mr. Green had a 63 percent approval rating. That was nearly three times Mr. Ige’s 22 percent approval rating, as voters seemed to credit Mr. Green — the public face of the state’s pandemic response — rather than the governor for the improving situation.

One of Mr. Green’s campaign ads this year highlighted the fact that Hawaii’s Covid infection rates have been among the lowest in the country, though they have still been devastating, particularly in Native Hawaiian communities.

But the main focus of the Democratic primary was housing. Hawaii’s comparatively low infection rate drew many wealthy remote workers from the mainland, exacerbating the state’s existing shortage of affordable housing — a crisis that, like the pandemic, has hit Native Hawaiians especially hard. As of July, Hawaii was the most expensive state in the nation to live in.

Mr. Green’s housing plan includes easing regulations to speed up home construction, allowing development on more public land and targeting illegal vacation units.

Ms. Cayetano — a businesswoman who co-founded Hawaii’s largest laundry services company and whose husband, Ben Cayetano, was governor from 1994 to 2002 — campaigned on creating a state-funded pipeline for renters to earn ownership of their homes, and on eliminating state income taxes for people earning less than $50,000.

Mr. Kahele, a first-term congressman and former state senator, focused more on campaign finance and governance issues than on housing, arguing that reforms like banning corporate campaign contributions and imposing term limits for elected officials would “break the barriers that keep average voters from steering our state government.”

But his campaign suffered after he decided to rely on Hawaii’s public funding system and then failed to file a document required to receive the money.