The death of former first lady Rosalynn Carter acts as a point of reference for almost a half century of American politics since her husband was president. She put mental health on the radar screen, she was a tireless political adviser to her husband, she was regarded as the “steel magnolia.” Courteous, charming, but driven and tough as nails.

Her life jars memories of the fall of President Richard Nixon, superb on the world stage but a corrupt, evil man in Washington. Rosalynn Carter’s life reminds us of the two-step process where both Gerald Ford and Jimmy Carter brought trust and decency back to the Oval Office even as neither was larger than life. For those of us who came to political consciousness in the 1970s, none of the three men who served as president rose to the level of “greatness” and one sank to the lowest levels of the American presidency.

Rosalynn Carter was a beacon of wisdom, hope and leadership in her own right, guiding her husband the biographers say throughout his career, including perhaps the most dramatic achievement of his presidency, the Camp David meeting between Egyptian President Anwar Sadat and Israeli Prime Minister Menachem Begin that led to the Camp David Accords.

Rosalynn Carter helped to complete the aura of trust and decency in the Carter White House as well as to redefine the role of the first lady. She was not a feminist’s feminist, but she gave women and adolescent females a role model to admire.

President Carter stood for human rights in the United States and around the world. He was not known for standing up to the Soviets — it would take Ronald Reagan to do that. Nor did he know how to handle the Iranians. He also did not command the kind of respect on Capitol Hill that led to major legislative achievements. Yet he did craft a national energy policy and create the Department of Energy and the Department of Education.

Although his presidency was marred by economic, energy and international crises, he still steadied the ship, did not lie to the American people, and prepared the way for both Reagan’s common sense conservatism and his own post-presidency greatness.

Jimmy Carter, like Gerald Ford, provided a vitally important bridge from the disaster of the Nixon presidency to the Reagan small-government revolution, the straight shooter, end of the Cold War but emotionally absent years of George H.W. Bush, and ultimately to Bill Clinton’s personally awkward yet deft and amazing effort to reinstate Democratic Party values in the context of a scaled back LBJ Great Society vision.

In many ways the country went back and forth between the government being too small to the government being too large from the 1960s to when George W. Bush -— whose reputation will improve as the war on terror plays a major role defining the next generation — became president and 9/11 brought us back to the world stage.

The Obama presidency was a game changer placing a Black man, strictly speaking a biracial man, in the Oval Office — brilliant, fair and trustworthy. He was not a good schmoozer, but he got us out of the financial crisis of 2008-09 and got a major health care law passed. Obama, like President Carter, was a good fit for the Oval Office, giving it the integrity and dignity it deserved.

Michelle Obama, like Rosalynn Carter, made things happen, said the right things and gave the public the impression that she was an integral part of the presidency.

In the Trump presidency we are back to Nixon and national disaster. Nixon had the Clean Air Act, and Trump had the Abraham Accords. Yet both men disgraced their office.

In Joe Biden, who has a great many unrecognized legislative achievements, we got some of President Carter as well as President Ford again when it comes to his character, a true public servant whose love for his country is always clear. Jill Biden, like Rosalynn Carter, exudes goodness, hard work and leadership.

Jimmy Carter has not been treated kindly by the presidential historians. Yet he and Rosalynn both did a great deal of good while they were in the White House. They each taught us a lot about integrity, honesty, hard work and patriotism.

Dave Anderson has taught political philosophy at five universities and edited the interdisciplinary volume “Leveraging.”