The outpouring of millions of demonstrators against the U.S. involvement in Southeast Asia that cost 55,000 American lives eventually led to a pullback and the first major military defeat in the nation's history. But it also contributed to the end of a well-meaning though wrongheaded mission, in which aroused public opinion at home essentially drove President Lyndon Johnson from the White House.
At the same time, the tenacious determination of American blacks and many white allies finally broke the back of the national disgrace of racial segregation in the South. The achievement was cemented toward the end by the strong leadership of the same Lyndon Johnson, who pushed through Congress the implementing legislation on voting and public accommodations rights.
In both cases, protesters in the streets eventually forced basic changes in government policy, in coordination with like-minded legislators who saw both the antiwar and civil rights protests as expressions of broader public revulsion.
The same has been true to a degree of the tea party protest against the growth and spending of the federal government. Its public clamor for reductions was central to the return of the House of Representatives to Republican control in the 2010 elections. The tea party led to the congressional supercommittee's effort to slash trillions from the federal deficit -- and contributed to its failure.
As for the Occupy War Street protest, there has been more heat than light generated to date, as its essentially leaderless participants have failed to identify and demand tangible steps to combat society's wild income inequality. Their contention that they are the 99 percent on the short end, compared to the 1 percent of the moneyed class who have most personal wealth, has caught on as a slogan. But then what?
The absence of a clearly identifiable action plan has made it easier for public officials like Mayor Michael Bloomberg of New York to use police to force out the Occupy squatters from the city's parks on grounds of public health and safety. It's still an open question whether such muscle flexing will bring public sympathy or revulsion toward the occupiers.
The protests in New York and other cities enjoy support from customary liberal and left-leaning groups, including organized labor. But the camping out is also a reflection of the nation's stagnant jobless rate, which stubbornly haunts President Obama's pleas for public patience.
The occupiers' energy, tenacity and determination, however, are resources that remain available to the president -- who professes to share the view of the self-proclaimed 99 percent -- if he can somehow harness and channel them into effective political action. Mr. Obama's efforts to deny the 1 percent the Bush tax cuts they still enjoy should be an easy recruitment tool for him among the complaining 99 percent.
So should his administration's efforts to enforce stronger regulations of Wall Street practices in the fields of home loans and banking foreclosures, changes he has been touting in recent speeches. However, in the absence of tangible results for troubled homeowners, President Obama has had little to show to make him welcome as a leader of the occupation movement, or even as one in sympathy with it.
His well-recognized caution about getting too close to the flame of public protests has kept him away from any of the occupation demonstrations, including the one near the White House. It has been a missed opportunity to march in a populist parade of uncertain destination and political value.
Indeed, many political leaders of both parties have given a wide berth to the Occupy movement across the country as it continues to declare, "We are the 99 percent," in the clearest expression in a long time of what the Republicans like Newt Gingrich so incessantly and derisively call "class warfare."
Jules Witcover is a syndicated columnist and a former long-time writer for The Baltimore Sun. His email is firstname.lastname@example.org.