Forty years ago, writes the Washington Post‘s E.J. Dionne, liberalism’s moments seemed to have passed:

From the death of John F. Kennedy in November 1963 until the congressional elections of November 1966, liberals were triumphant, and what they did changed the world. Civil rights and voting rights, Medicare and Medicaid, clean air and clean water legislation, Head Start, the Job Corps, and federal aid to schools had their roots in the liberal wave that began to ebb when Lyndon Johnson’s Democrats suffered broad losses in the 1966 voting. The decline that 1966 signaled was sealed after April 4, 1968.

I’m struck by the fact that another great burst of liberal legislation took place almost exactly 100 years prior, during the Civil War, when the reactionary Southerners were not in Congress: the Land-Reform colleges were set up, the Homestead Act was passed, giving millions of farmers access to farms and economic powers, and the first intercontinental railroads were built.

Can we start a new wave of progressive legislation 40 years after the last one instead of 100? Actually, progressive waves had been coming every 30 years or so, from the Populists in the 1880s to the Progressives in the 1900s to the labor and other movements of the 1930s.

April 4 is also the 41st anniversary of one of Martin Luther King Jr.’s greatest speeches, at the Riverside Church in New York City condemning the Vietnam War. He called on those who did not ordinarily want to cross boundaries of action to do so, because all of human oppression (and we may add ecological, a sentiment I’m sure he would have shared) is a part of a whole of a particular social configuration:

“A time comes when silence is betrayal.” And that time has come for us in relation to Vietnam. The truth of these words is beyond doubt, but the mission to which they call us is a most difficult one. Even when pressed by the demands of inner truth, men do not easily assume the task of opposing their government’s policy, especially in time of war. Nor does the human spirit move without great difficulty against all the apathy of conformist thought within one’s own bosom and in the surrounding world. Moreover, when the issues at hand seem as perplexed as they often do in the case of this dreadful conflict, we are always on the verge of being mesmerized by uncertainty; but we must move on.

Substitute the word “Vietnam” with Iraq, global warming, global poverty, and ecosystem destruction. We must move on.