From 1961 to 1966, the Reverend Martin Luther King Jr. wrote an annual essay for The Nation on the state of civil rights and race relations in America. His 1965 contribution, "Let Justice Roll Down," which originally appeared in the March 15, 1965 issue of the magazine, was both timely and timeless.

So is his oratory. Thanks to YouTube we can watch King’s I Have a Dream speech given on August 28, 1963 on the national mall in Washington, DC, near the spot where Barack Obama will take his oath of office on Tuesday.

Martin Luther King’s birthday has been a federal holiday since 1986, although it took many years for all 50 states to observe it. Yet for many people, especially those old enough to have witnessed the civil rights struggle, this year’s observances, taking place on the eve of Obama’s historic inauguration, have added significance.

"On Monday we celebrate Martin Luther King, and on Tuesday we celebrate our first black president. I have to punch myself sometimes — it’s hard to explain how I feel. It’s life-changing," Mrs. Sheryl Goodine, of Long Island, a civil rights movement veteran, recently told the New York Times.

What I believe is the most important part of King’s vast legacy to remember this year is the civil rights leader’s firm belief in the importance of building a grassroots movement to pressure whoever is in power. As recounted in Bruce Wallace’s conversation with King biographer Taylor Branch, King always understood that the only way to the mountaintop is through tremendous pushing from below.

In this era, pushing Obama past corporate interests and his own prudent inclinations to a new politics that puts people first will take an unprecedented grassroots effort. This, to me, is the main lesson to draw as we contemplate King’s life and work on the national holiday in his honor.