Nadao "Najo" Yoshinaga, a veteran of the famed 100th Battalion/442 Regimental Combat Team in World War II and who helped Democrats capture the Territorial Legislature and shaped the party's approach to social welfare, died Tuesday. He was 90.

Yoshinaga, an attorney from Wailuku, Maui, was elected to the Territorial House in the Democratic takeover of 1954, when the party broke the Republican hold on Island politics. He moved to the Territorial Senate in 1958 and was an influential leader on issues such as labor, health care, technology and the arts until he retired from the state Senate in 1974.

He was an advocate for a higher minimum wage, unemployment compensation and worker rights. He pressed for a study on universal, employer-based health care that helped lay the groundwork for the state's landmark Prepaid Health Care Act of 1974. The law requires businesses to provide health insurance to employees who work 20 hours a week.

Yoshinaga, an often volatile, bare-knuckled insider, was also considered a visionary. He supported funding for research into marine biology, geophysics and observatories, while also backing the creation of the State Foundation for Culture and the Arts.

He proposed bills on population control and limiting the number of automobiles to force a conversation on growth, years before the term "sustainability" became popular at the state Capitol.

After he left office, he was a mentor to many young Democrats, challenging them to push harder on issues such as food and energy independence.

"He was a mentor to a whole community of folks who surrounded him," said former state lawmaker Jim Shon, who was among friends who wrote a tribute to Yoshinaga in The Advertiser last summer.

"I think he really inspired a lot of people to not just coast."

U.S. Sen. Daniel K. Inouye, D-Hawai'i, who was also a 442nd veteran elected to the Territorial Legislature in the Democratic takeover, said Yoshinaga had compassion for the needy.

"He had the reputation for being a tough, no holds barred political leader," Inouye said in a statement. "He was feared by many but for those who knew him, he was a softie.

"He was caring and compassionate toward those in need. He had much to do with the establishment of employer-mandated health care in Hawai'i and helped Hawai'i become the first state to support agricultural workers' right to unionize. Hawai'i will miss Najo. I will miss Najo."

State Sen. Carol Fukunaga, D-11th (Makiki, Pāwa'a), who met Yoshinaga just after she left law school, called him an extraordinary person and a "giant" on tax and policy issues in the formative years of the Legislature after statehood.

In his later years, as a mentor, she described him like the character "Yoda," the Jedi master from the "Star Wars" movies.

"He was sort of like that, but he was always very self-effacing and not really seeking the limelight," she said. "But he really was just so pivotal in so many ways."

Yoshinaga went to Wailuku Public School, Maui High School, the University of Hawai'i and DePaul University in Chicago for law school.

After his retirement from the Senate, he served as chairman of the state Labor and Industrial Relations Appeals Board.

State Sen. Jon Riki Karamatsu, D-41st (Waipahu, Village Park, Waikele), met with Yoshinaga nearly every week to talk policy and politics. He considered him a visionary who still had sharp observations about Hawai'i's future.

"First, he was a friend," he said. "And second, he was a big, big political mentor to me."