THE LATEST ENTRY in the national Truly-New-Idea Contest comes from the Committee on the First 100 Days of the House Republican Research Committee. Not to be outdone by the new ideas of "Atari Democrats" (whose party the report calls a "loveless marriage between the New Deal and the Big Chill"), the 100-Day Committee offers "a road map of where we want to lead America."

If you follow along the path described in the committee's road map, you will spy many familiar landmarks. Here is the now-obligatory quote from JFK, there the required one from FDR. Here is the expected affirmation that "America's real energy comes not from government, but from millions of good hearts and creative minds." Over there is recognition that "society is only as strong a its families." And over there is . . . "America is a rainbow coalition." How did that get in there?

So what else is new? Not much. There are some possibly useful but modest ideas to help handicapped people find jobs, promote adoptions, retrain workers and reduce soil erosion. There is welcome support for immigration reform, the Treasury's tax reform proposals and strengthening basic environmental laws, and an endorsement of a Democratic idea to require new spending bills to specify how they will be financed.

The "civil rights" section proposes new fines and prison sentences for damaging or stealing religious property. Under the heading "Sunshine in the House" appears a requirement for "honesty and accuracy in the Congressional Record" -- an idea that, constitutional objections aside, could certainly save time in floor debate.

There is expressed concern about the deficit. Notably absent, however, is any concrete plan for dealing with it, only the tired, old call for a balanced budget constitutional amendment and for "broad- based spending reductions" not otherwise specified. In fact, although the report discreetly avoids putting price tags on its proposals, its ideas would expand the deficit substantially.

That result would not come, of course, through the old-fashioned method of authorizing programs and voting money for them. Rather, all the new ideas are to be paid for by the far less obvious -- and less controllable -- method of giving tax breaks: tax breaks for investors, homemakers, displaced homemakers, day-care users, companies that train workers, builders of privately owned prisons, people caring for elderly relatives and parents with children in private schools. Consequently, the Treasury would lose still more revenue, the deficit would grow, and spending for basic social programs would have to be cut still more.

Now where did we hear that idea before?