Washington (CNN) In October 1980, when Ronald Reagan's presidential campaign appeared to be lagging, his strategists suggested he appeal to female voters by promising to put a woman on the Supreme Court .

In its two-century history, no woman had ever been nominated, and Reagan's announcement at a Los Angeles news conference made front-page headlines.

But when presidential candidate Joe Biden first declared in South Carolina he wanted to name a black woman to the Supreme Court, and when Rev. Jesse Jackson recently said in Michigan he was endorsing Bernie Sanders because he personally promised to name an African-American woman justice, the statements drew little notice.

The same was true Sunday night at the CNN debate, when Biden repeated his commitment to a black woman on the court. Audiences understandably seized on his additional, fresher vow to choose a woman as his vice president.

No African-American woman has ever been nominated. Among the 114 justices who have served since 1789, there have been two African-American men (Clarence Thomas and the late Thurgood Marshall) and one Latina ( Sonia Sotomayor ).

Pledges of a Supreme Court "first" have become a recurring theme on the presidential trail. Republican George W. Bush's 2000 and 2004 campaigns raised the possibility of a "first Hispanic." Candidates certainly make a play for important demographic constituencies with such assertions, but they also reflect a belief that the court, ruling on matters from abortion rights, to the death penalty, to government separation-of-powers, should appear to represent all Americans and offer equal justice.

Perhaps the scant attention to Biden and Sanders statements regarding race at the Supreme Court can be chalked up to general public expectations that these two candidates already would be seeking diversity, based on Democrats' general record on appointments. Neither Biden nor Sanders surrounded their comments with the hoopla of Reagan's back in 1980.

Yet if one of today's candidates follows through, he would inject not only fresh racial character onto America's highest court but also a wider range of professional experience.

That is because he would necessarily look beyond the usual pool.

Of the 14 justices appointed to the Supreme Court since 1975, only two did not come from federal appeals courts: Sandra Day O'Connor, who was serving on an Arizona state court when Reagan chose her to be the first woman justice in 1981, and Elena Kagan, who was US solicitor general, arguing cases before the justices, when President Barack Obama selected her in 2010.

Right now, only four US appeals court judges are African-American women, out of about 180 actively serving US appeals court judges, according to the Federal Judicial Center. All four turn 69 or older this year. A new president would certainly not select a nominee for a lifetime seat who was on the cusp of age 70 or older.

Among the possible African-American candidates whose names have been circulated by liberal advocates over the years are: US District Court Judge Ketanji Brown Jackson, in Washington, DC, 49; California Supreme Court Justice Leondra Kruger, 43; and NAAACP Legal Defense Fund president Sherrilyn Ifill, 57, and New York University law professor Melissa Murray, 44.

More names would likely be in the mix, should a Democrat win the White House and a vacancy arise. Two earlier Democratic appointees are now in their 80s and may choose to retire in upcoming years: Justice Ruth Bader Ginsburg, who turned 87 on Sunday, and Justice Stephen Breyer, who will be 82 in August.

Trailblazers

President Lyndon B. Johnson broke ground when he named Thurgood Marshall. In June 1967, as he announced the elevation of Marshall, the US solicitor general and a former US appeals court judge, Johnson said, "He is the best qualified by training and by very valuable service to the country. I believe it is the right thing to do, the right time to do it, the right man and the right place."

Reagan acted on his "first woman" pledge a few months after winning the White House when a vacancy arose. He selected O'Connor , then 51 and a judge on an intermediate Arizona state court. O'Connor, a former state senate majority leader, had deep political and legal connections. Her name had been quietly passed on to Reagan's top aides in 1980 and early 1981 from various Republicans, including then Chief Justice Warren Burger, who had met O'Connor on a houseboat vacation on Lake Powell in Utah. They became friends.

For decades, back to the administrations of George H.W. Bush (1989-1993) and Bill Clinton (1993-2001), presidents intimated they were considering putting the first Hispanic on the Supreme Court. But it did not happen until 2009 with Obama's appointment of Sotomayor, who was then a judge on a US appeals court in New York. Sotomayor's parents had been born in Puerto Rico.

Biden, now the frontrunner for the Democratic nomination, first said during the February 25 debate in Charleston: "I'm looking forward to making sure there's a black woman on the Supreme Court, to make sure we in fact get every representation." In Sunday's debate, he directly vowed to choose an African-American woman for the court, and in pledging to name a woman as vice president, he said he wanted his administration to "look like the country."

The former vice president to Barack Obama has distinct experience related to the judicial selection process. As a longtime senator, before becoming vice president, he served as a Senate Judiciary Committee chairman, overseeing Supreme Court confirmation hearings. He expressed aspirations for nominees over the years, including for more varied backgrounds and academic credentials. All current nine justices hold Ivy League law degrees, and a majority of the nine once served in their early careers as Supreme Court law clerks.

In 2005, shortly after Justice O'Connor announced she would be stepping down, the Senator Biden told CNN's John King he wanted "someone who knows life experience."

Said Biden, "We have enough academics on the court."