Twenty-five million Americans are poor, according to the National Advisory Council on Economic Opportunity. Another 30 million -- if they lose a job, get sick or burn out -- could be poor. Those among both groups who have been served modestly these past years by the Coomunity Services Administration need not have worried when that federal agency closed last week.

They have the comforting words of Martin Anderson, once an adviser to Richard Nixon and now President Reagan's chief domestic adviser: "The 'War on Poverty' that began in 1964 has been won; the growth of jobs and income in the private economy, combined with an explosive increase in government spending and income transfer programs, has virtually eliminated poverty in the United States."

That was a 1978 statement, uttered when conservatives like Anderson, as outsiders mumbling to themselves, could issue such unfounded declarations and have them ignored as right-wing cant.

But two years later, in December 1980 when Anderson was on his way to the White House to serve Ronald Reagan, he was pushing the same line: Poverty had been "virtually wiped out in the United States, our systems of government aid had been a brilliant success. . . . They should now be dismantled."

What had been the idlest of theories in 1978 had become, through an election, a powerful threat.

Last week, with the closing of CSA (it administered 900 locally lrun community-action programs and was the successor to the Office of Economic Opportunity that created Head Start, Job Corps, Legal Services, Upward Bound, Foster Grandparents and other enduring programs) a threat became a fact.

Aside from being a devastating turning away from the poor, the dismantling of CSA creates another devastation: the dismantling of a respectable conservative philosophy.

In 1964 when the Economic Opportunity Act was passed, the bootstrap argument was pushed by many Republicans. Washington can't do everything for the poor, they said. OEO's business must be hand-ups, not hand-outs.

These were arguments with some merit. That the agency's programs were run with them in mind explains the congressional support OEO received in the mid-1960s f rom Republicans like Bradford Morse, John Dellenback, Peter Frelinghuysen and Alphonzo Bell. If this part of Republican philosophy hadn't been in a program like Community Action, they would not have voted for it. But it was, and they did.

The difference between those Republicans -- all are gone now -- and ones like Martin Anderson today is that of open minds and closed minds. A Morse or Bell, or even carping opponents of OEO like Albert Quie and Charles Goodell, could at least be debated with. Some would have liked to wish away Sargent Shriver and his liberal zeal, but wishing away poverty was never though of.

The final days of CSA were marked by the publication of the final report of the advisory council. Its statistics give the lie to Anderson's claim that America's poverty is no more:

In 1969, the poverty rate among black families in central-city areas was 21.5 percent. In 1979, it rose to 28.5 percent.

For poor children, the rate of overty increased by more than 15 percent from 1969 to 1979. In 1978, 40 percent of the nation's black children were poor and so were 25 percent of Hispanic children.

700,000 more citizens were poor in 1979 than in 1978.

The council's report concludes: "At present, there exists an air of suspended disblief over the radical changes that have occurred in the past months. That is because the layoffs, the shutdowns, the cutbacks and the reduced paychecks have not yet reached ground level. . . . October 1, 1981, will be remembered as a day of infamy, for it will mark the worst masacre of social and human services in American history."

When Regan policymakers say that poverty doesn't exist, it brings to mind James Baldwin's comment in the early 1960s. When many whites said that racism was no problem, he told the, "You have no right not to know."

The right not to know about racism had not legitmancy then, and the Reagan administration's ignoring of poor has none now.