Next week, almost six months after he first announced the "bold, innovative" program as the centerpiece of his State of the Union address, President Reagan is going to try to breathe some life into his all-but-forgotten federalism initiative.

Two days after he gets back from vacation, he will go to Baltimore to address the National Association of Counties (July 13). In that speech and the attendant press briefings, Reagan will spell out what has happened to his plan to turn back responsibilities and revenues to the states, since it was introduced last winter.

He will try to impart some momentum to an idea which has been buried in the unending battle of the budget, the demands of world crises and the upheavals inside the administration.

The Baltimore speech will be followed quickly by a meeting of the President's federalism advisory committee, headed by his friend, Sen. Paul Laxalt (R-Nev.), and then a high-level White House session to thrash out the final decisions on the program.

And then, many months late, the Reagan plan will at last be sent to Congress. Not the Reagan legislation, mind you, but a detailed outline of the program. When the actual legislation will be ready--well, really, no one is able to say.

It is easy to mock this procedure. Indeed, three months ago, when the negotiations over the original outline seemed to have reached a deadlock, the proposal was pronounced dead in this space.

That was wrong. Its revival next week suggests not just the protracted infighting that this seemingly simple suggestion has provoked, but the genuine determination of Ronald Reagan to push ahead with the idea.

It is fair to say that while cutting down big government is, in general, a popular idea, the constituency for Reagan's specific proposal is not very large; even inside the White House, there are those who deride the idea as a never-never land suggestion.

But Reagan really believes, as he said in January, that "a single, bold stroke" of devolution is needed to restrain the growth of the federal government and revive the responsibility of the states.

And so he keeps poking the idea back to life and prodding for action even when other problems have had to be given priority. Discussions between administration aides and representatives of state and local government have been going on throughout this period, and the plan of today is not the same as the plan with which Reagan began.

The President, bowing to strong criticism, has dropped his original idea of moving the federal food-stamp program back to the states. Instead of financing transition costs of programs that are going to the states largely from the temporary federal oil windfall-profits tax, he has agreed to put general revenues into the trust fund for that purpose.

Those are big concessions on his part. In return, some of the state and local officials have agreed to reconsider their traditional positions and look again at his idea of federalizing Medicaid but turning the other big welfare program--Aid to Families with Dependent Children--over to the states.

But it is by no means certain how many will embrace the Reagan plan, even with its modifications. The county officials probably will; otherwise, Reagan would not be making his speech there. The state legislators may endorse it, with reservations, later this month at their meeting in Chicago. But the governors, who meet in Oklahoma in August, are thought unlikely to give it the two-thirds vote needed.

The skepticism among city officials is probably even greater than at the state level. Indeed, in an election year, when partisan considerations virtually require most Democrats to denounce any Reagan domestic initiative as a heartless rip-off of the hardest-up, it will be hard for any Democrat facing re-election to say it's a grand idea.

Considering that there is no chance that the program will be passed by this Congress this year, there are some in the White House who argue that Reagan is doing nothing more with his speech next week than offering the opposition another inviting target. One official told me he is sure that New York Mayor Ed Koch, playing to the liberals in pursuit of the Democratic nomination for governor, will be on the air within minutes after Reagan finishes, denouncing him for "dumping welfare" on the states.

So why do it? The answer, so far as I can learn, is that Reagan is anxious to have hearings in the Senate Finance and Government Operations committees this year, to measure congressional and interest-group reaction. And then he intends to come back with a further-revised program in January, 1983, and really push for its passage.

"We have learned a lot in the last six months," said Richard S. Williamson, the White House assistant who has handled this project. But the most important lesson may simply be that Reagan is dead-serious about this project.