In the mid-1960s, when everything liberal seemed to come up roses and programs like Job Corps, Head Start, Foster Grandparents, Legal Services and VISTA blossomed like springtime itself, it was accepted that these were liberal programs.Liberals like Sargent Shriver at the old Office of Economic Opportunity created them. Other liberals -- Joseph Califano in the Lyndon Johnson White House -- lobbied for them, and liberals in Congress funded them.

That analysis was simplistic. A number of people knew better, especially Shriver. These are programs, he argued, that have a built-in appeal for conservative Republicans who want to go beyond ideology: Money is thrown at problems, all right, but in a few years the money gets thrown back, sometimes double or triple the cost. In addition, the programs have minimal federal involvement.

Time has proven Shriver to be uncannily accurate.A few days ago, Sen. Orrin Hatch, the Utah conservative who is the new chairman of the Senate Committee on Labor and Human Resources, sounded like the upbeat Shriver of old in defending the Job Corps. Hatch warned his soul mates in the Reagan administration: "Here at last . . . is a government job training program that provides jobs and saves more dollars than it expends . . . . The Job Corps has been a leader in synthesizing methods and materials to educate and train the most hard-core disadvantaged."

In a throwback of its own in the 1960s, the Reagan budget-trimmers, as they were about to knife into the Job Corps, repeated an argument Richard Nixon used in his 1968 campaign: that it costs more to put someone through the Job Corps than through Harvard. Hatch said this was ridiculous. He told a reporter, "We're talking about functionally illiterate kids who stand no chance whatsoever of going to Harvard, or any other university for that matter. We're talking about saving kids from a lifetime on the public dole."

That was the liberal sentiment 16 years ago, except that Hatch the conservative speaks with even greater authority today. He has visited established Job Corps centers. He has read the performance studies, which have been positive.

With Hatch proclaiming that the "public investment in the Job Corps is economically efficient," the Office of Management and Budget has changed its mind and will leave the program intact.

If a few field trips to Job Corps centers impressed Sen. Hatch, the same approach led Nancy Reagan to become an advocate of Foster Grandparents. The program, in which low-income elderly citizens work 20 hours a week caring for children who may be handicapped or retarded, operates in more than 200 sites. With Mrs. Reagan's enthusiasm -- her involvement goes as far back as 1967 in Sacramento and as recently as a trip a few days ago to a center in Prince George's County, Md. -- the program's budget of $48 million is to be increased next year.

Head Start is also safe. In fact, so many politicans have come to know its excellence that it was one of the Reagan administration's "safe seven" programs.

But what of all the others that aren't safe? Are they to be cut or abolished merely because no Orrin Hatch or Nancy Reagan has kindly regards for them? Are we to have a policy for pet programs?

If Legal Services, VISTA and similar poverty programs now operated by the Community Services Administration are under attack and with no patron with clout to protect them, then we are back to the simplism that prevailed when the programs began in the mid-1960s: They are the creations of liberals. This being an administration of conservatives, ideology alone is justification to batter them.

If anything, officials of most of the threatened poverty programs have strained to be apolitical. They understood that to be even suspected of leftish leanings creates useless trouble.

Comes David Stockman, a teen-ager when legislation establishing many of these programs was passed.Neither he nor Reagan has offered detailed evidence that the poverty programs aren't working or are wasting money or that the need has vanished.

It is to be imagined that congressional appropriations or oversight committees have been fooled all these years? Or that conservatives like Hatch, as wary as anyone about do-gooders and turf-protecting bureaucrats, have let their guard down?