US Senator Daniel Inouye speaks at the Japanese Cultural Center in Honolulu. (AP Photo/Marco Garcia, File)

Daniel Inouye, who as the son of Japanese immigrants petitioned his government for the right to serve in World War II and then earned the Congressional Medal of Honor for that service in the fight against fascism, became the highest-ranking Asian-American political figure in the United States.

Indeed, at the time of his death Monday at the age of 88, Inouye was third in line to the presidency.

But he never stopped confronting power on behalf of the rights of people of color, people with disabilities, women, lesbians and gays and political dissenters to equal justice and equal opportunity. A modest man who served in the Senate for more than fifty years, Inouye was not always accorded proper recognition of his historic advocacy on behalf of civil rights and civil liberties. But that is the error of those who underestimate Inouye, not of the senator. Indeed, as Vice President Joe Biden, who knew Inouye better than most in Washington, said after the senior senator’s death: “To his dying day, he fought for a new era of politics where all men and women are treated with equality.”

The American Civil Liberties Union got it right when the group hailed Inouye as “a champion of civil rights and civil liberties” who recognized that his own political successes required him to champion the rights of others. He did so when it mattered most. Inouye was the last sitting senator to have participated in the great debates over Southern segregation. And unlike other senior senators who have died in recent years after long tenures, he was on the right side of those debates.

The last sitting senator who joined the epic struggles to pass the Civil Rights Act and the Voting Rights Act, he led the fight for the Americans with Disabilities Act and was a key sponsor of the constitutional amendment to extend voting rights to 18-to-20-year-olds.

Inouye battled for reparations for Japanese-Americans who were interned in government compounds during World War II. And he was a passionate defender of the right to dissent. Indeed, the ACLU recalls, “Senator Inouye fought every iteration of proposed constitutional amendments to ban flag desecration—support that was particularly meaningful to the defense of free speech because of his military service.”

Inouye was one of the handful of senators who rejected the discriminatory Defense of Marriage Act in the 1990s and he emerged as one of the earliest and most determined backers of marriage equality in the Senate, asking: “How can we call ourselves the land of the free, if we do not permit people who love one another to get married?”

When the debate over whether gays and lesbians serving in the military arose, Inouye declared as a Congressional Medal of Honor recipient: “In every war we have had men and women of different sexual orientation who have stood in harm’s way and given their lives for their country. I fought alongside gay men during World War II, many of them were killed in combat. Are we to suggest that because of their sexual orientation they are not heroes?”

That was classic Dan Inouye. He never hesitated to use his own experience, as a genuine “greatest generation” American hero, as tool for championing the rights of all Americans.

Inouye’s advocacy across a career that brought him to Washington in 1959—as one of Hawaii’s first congressional representatives—was perhaps best illustrated in a remarkable 1968 keynote address to the most tumultuous Democratic Nation Convention in the party’s history.

Addressing a deeply divided convention just four years after he joined fellow senators in breaking the filibusters and advancing landmark civil rights legislation, Inouye stood before a convention where many delegates had been on the other side of the fight. He did so as a World War II hero, a Bronze Star and Purple Heart (and later Medal of Honor) winner whose arm was amputated in a field hospital on the edge of an Italian battleground. And he quietly demanded that the delegates recognize the sacrifices of all Americans.

“This is my country,” the 43-year-old senator declared on that hot summer night. “Many of us have fought hard for the right to say that. Many are now struggling today from Harlem to Da Nang that they may say this with conviction. This is our country.”

The Democratic convention of 1968 is usually remembered for the wrangling over the Vietnam War—which Inouye, who had been an ally of Lyndon Johnson’s administration, decried as “immoral” in his remarks. But Inouye, the first person of color ever to deliver a keynote address, devoted his remarkable speech to a deep discussion of lingering racism in the land, and by extension in a party that would that fall see many “solid South” states back the renegade third-party presidential run of Alabama segregationist George Wallace.

Less than a quarter century after Japanese-Americans were confined to internment camps, the young senator spoke of his Japanese ancestry. But he pointed out that racism takes many forms, explaining to the convention and the nation that, though he was a person of color, his circumstance was different from that of African-Americans in Southern states and inner cities.

Recalling a businessman who challenged his advocacy for civil rights after the urban riots of the 1960s. “Tell me,” the man asked, “why can’t the Negro be like you?”

“First, although my skin is colored, it is not black,” Inouye explained. “In this country, the color of my skin does not ignite prejudices which have smoldered for generations. Second, although my grandfather came to this country in poverty, he came without shackles. He came as a free man enjoying certain constitutional rights under the American flag.”

For African-Americans, in particular, the barriers had been cruder and more violent.

Recalling his speech four decades after the fact, in an interview with the Honolulu Advertiser newspaper, Inouye expressed delight that a young man who had grown up in Hawaii would be nominated by his party as its presidential candidate at the Democratic National Convention.

But Daniel Inouye was not satisfied.

“You know,” he reflected, “after all these years—40 years later—racism is alive and doing well.”

That was Daniel Inouye in 2008, speaking as he had in 1969, bluntly, truthfully, about the racial divisions that still haunt America and the struggle to make the Democratic Party and the nation recognize and confront the causes of those divisions.

How can the Democratic Party carry on Daniel Inouye’s legacy of progressive politics? Find out here.