I will be in Washington, D.C., on Jan. 21 for the second inauguration of our president. Fittingly, this year’s inauguration coincides with the national observance of the birth of Dr. Martin Luther King Jr.

As President Barack Obama has frequently stated, it was King and other freedom pioneers who forged the path that enabled a community organizer and African-American child of a single mother to travel to the highest office in our land.

Residing in that office has not been easy. The president’s first term posed great challenges. However, I believe, given the deep economic crisis he inherited, a punitive and obstructionist Congress and extremist opposition in statehouses across the country, Obama can point to important achievements in key areas: health care, the economy, women’s rights, immigration reform and gay rights, among them.

And I believe the president has the opportunity to do even more in his second term. He can be a truly transformational president by broadening and deepening needed reforms. However, that does not depend on him alone. What we, the progressive coalition that returned him to the White House, do during the next four years will help write that legacy.

King taught us how. During the last years of his short life, he shifted the focus of his work from civil rights to the broader, fundamental battle for basic human rights, especially economic justice.

King, a master organizer, knew that the courage and foresight of individual leaders were important but of little significance unless harnessed to organize the strength of ordinary working people. King also strove to connect the labor and civil rights movements, envisioning them as twin pillars for social reform and our nation’s advancement.

“Let us rise up tonight with a greater readiness,” King said in Memphis in support of striking sanitation workers the night before he was assassinated. “Let us stand with a greater determination. And let us move on in these powerful days, these days of challenge to make America what it ought to be. We have an opportunity to make America a better nation.”

Obama, the Chicago community organizer, often said that change comes not from the top, but from the bottom up, and pressure from the base is what is needed to help make Obama a transformational president.

One transformational president was Franklin Delano Roosevelt, who said famously to trade unionists who were pressing him for important reforms, “I agree with you. Now go out and make me do it.”

It was the strength of labor and radical organizations in the 1930s and 1940s that pushed Roosevelt to sign some of our nation’s most important measures, including unemployment compensation, Social Security, unprecedented labor law reforms and far-reaching public works programs.

Today, critics are hailing the film “Lincoln,” which recounts the struggle of another transformative president to win passage of the 13th Amendment to the Constitution, which abolished slavery. However, without the abolitionist movement, labor solidarity and the achievements of African-American soldiers, Abraham Lincoln would not have secured his place in history. He, too, understood the central role of working people to our nation’s advancement. He said during his first inauguration in 1861: “Labor is prior to, and independent of, capital. Capital is only the fruit of labor and could never have existed if labor had not first existed. Labor is the superior of capital and deserves much the higher consideration.”

During the next four years, Obama will be pressured by those representing corporate and big-moneyed interests and by those representing working and poor people. It is our unity and organization that can help him do the right thing. In that regard, it would be wise for us to keep intact the coalitions that helped win the president’s re-election.

Obama said during the 2011 unveiling of the King monument in Washington, “And so with our eyes on the horizon and our faith squarely placed in one another, let us keep striving; let us keep struggling; let us keep climbing toward that promised land of a nation and a world that is more fair, and more just, and more equal for every single child of God.”

Let us keep struggling. Obama can lead our nation to great gains in the next four years. But it won’t happen without us.