It began last summer when Ronald Reagan, in accepting the Republican nomination for president, startled millions of listeners by quoting the Democratic hero of heroes, Franklin D. Roosevelt. More recently, incoming budget chief David Stockman has produced an economic manifesto calling on Reagan, in his first "100 days," to declare a "national economic emergency" and to launch an Emergency Economic Stabilization and Recovery Program. Sen. Robert Dole, about to be Finance Committee chairman, favors that declaration, but Treasury Secretary-designate Donald Regan resists the idea as the product of a "worst-case" analysis. GOP Rep. Jack Kemp, Stockman's manifesto co-author and a father of Reagan's proposed 30 percent tax cut in three equal installments, has said of the new president that "I think he's going to be the Franklin Delano Roosevelt of the Republican Party."

What's going on here? GOP calls for another New Deal? In terms of substance, of programs, certainly not. But in terms of political psychology, exactly that. What is now being argued among the new GOP power brokers is whether to create a Reagan-Republican counterpart of the FDR-New Deal "first 100 days" that launched nearly half a century of Democratic political dominance by beginning to pull the United States out of the Great Depression.

In short, Ronald Reagan is being urged to follow, or advised not to follow, the FDR example: seize the moment of national discontent, draw at once Congress with a flood of specific legislative requests and a flurry of executive actions, push through a comprehensive economic program in those first 100 days of the new administration.

How President Reagan decides is likely to be the first major landmark of his administration, one that will color his entire tenure in the White House.

The atmosphere today may not precisely resemble that between the election and inauguration of FDR 48 years ago. Deflation, not inflation, including massive unemployment, business bankruptcies and bank failures then were the critical concerns. Nothing like that exists today.

But there is a parallel to the mood of that yesteryear.FDR was not elected in his own right because he had a plan, enuniciated during the campaign, to end the Great Depression. He was because Herbert Hoover was thrown out of office as a failure; Reagan likewise won chiefly because Jimmy Carter was judged a failure. In that sense, Reagan has the opportunity, just as FDR did, that arises from a national mood that says "do something; try just about anything; the current situation is intolerable." At least a good part of the nation now seems to feel that way.

When FDR took the first of his four presidential oaths on March 4, 1933, every bank in the nation had closed its doors. He began by telling Americans that "the only thing we have to fear is fear itself."

In his now famous first 100 days (actually 103 days beginning with inauguration and ending when Congress adjourned on June 15), president and legislators together created 15 major laws. They reestablished the banking system and insured bank deposits, enforced government economy, abandoned the gold standard in public and private affairs, created mechanisms to put a floor under farm prices, refinanced farm and home mortgages, created a system of self-government for business and industry that included the right of collective bargaining, minimum wages and maximum hours, set up a national relief system for the destitute, a massive public works program, the Civilain Conservation Corps and the Tennessee Valley Authority and other related activities. All these actions were designed to pull the nation out of the Great Depression and to create public confidence in the future of America.

It is true, of course, that many of these laws were challenged in the courts as unconstitutional and that some of them were so held by the Supreme Court. It also is true that not until the beginning of World War II did the United States finally shake off the depression's effects on the economy. But what is relevant to today is simply that a new administration replaced a period of torpor with a whirlwind of activity that, in a later phrase, got America moving again.

There were bitter internal fights in those early New Deal years, a major one between economizers in government and those who believed that deficit spending was the only solution. One can see a parallel between FDR's budget director, Lewis W. Douglas -- who wanted to slash government spending 25 percnet and who stood up to, and temporarily defeated, the most powerful lobby of the day, the World War veterans -- and Reagan's budget chief, Stockman. Both resigned House seats to take the job -- Douglas was 38, Stockman 34 -- and both had a passion for economy, Douglas finally lost out to the big spenders; Stockman already is under attack by both fellow Republicans and Democrats.

In 1933 FDR was able to pay little attention during the 100 days to foreign affairs; that may not be so easy for Reagan to do this time. Some early New Dealers wanted FDR to go so far as to nationalize the banks; some current Reaganites seem to want him to repeal a lot of laws now on the statute books. FDR rejected such advice; what Reagan will do we do not yet know.

Reagan wants to "land running" on Jan. 20, as the phrase has it. But how far and fast will he run from there? Whatever one's opinion today of the early New Deal, it is worth recalling Walter Lippmann's judgment: From a "congeries of disorderly panic-stricken mobs and factions," the first 100 days produced "an organized nation confident of our own power to provide for our own security and to control our own destiny."

It is that change in the psychology of America that remains as the historic achievement of those first 100 days. By summer of 1981 we may be able to draw at least a tentative judgment on Ronald Reagan's first 100 days.