YOU COULD be forgiven for wondering whether the Ronald Reagan you've been hearing these past few weeks is the same Ronald Reagan you heard campaigning for president in 1980. The 1980 version ran on a platform of cuts in taxes and government spending, a more assertive foreign policy and a government more respectful of traditional cultural values. But for most of this summer, Mr. Reagan has been sounding other themes. He has been speaking extensively on the need for better education (and has not highlighted his 1980 promise to abolish the Department of Education). His administration has proposed a stronger open housing law and brought lawsuits against various forms of racial discrimination. He has announced a task force to study hunger. He has met with photographer Ansel Adams, an outspoken critic of Interior Secretary James Watt. Even on Central America, he has denied that our naval maneuvers are extraordinary and stressed his desire for peace.

In other words, Mr. Reagan is acting like a campaigner, repeating himself again and again so that inattentive voters will notice what he's trying to say. In the process he is enraging some of his most faithful supporters, who want to see the Reagan who thrilled them in 1976 and 1980. But the Reagan of 1983 is a campaigner who is taking his base for granted and trying to win over the opposition.

Concentrating on the opposition's issues--education, civil rights, the environment--can, of course, be a dangerous business. In the final weeks of a campaign, it is a sign that a candidate is in trouble. But spending time on them 15 months before an election may prove to be shrewd politics. On civil rights, for example, Mr. Reagan probably does not expect to change the votes of many blacks by his flurry of activity. But he might reduce the intensity of their negative feelings toward him. The political risk is that he may undermine the enthusiasm of his base without winning over converts. But the bloc of voters currently very negative to Mr. Reagan is uncomfortably large, and so, evidently, he thinks that it is worth alienating his strong supporters in order to mollify some of the detractors.

An incumbent president in any case is usually reelected or rejected on the basis of big issues--the economy, foreign policy. On these Mr. Reagan has set his course and is evidently prepared to stay it and brave the dangers. His summer strategy of mollifying the opposition will in the long run be secondary to his standing on these major issues. Candidate Reagan in 1980 could in part attribute his victory to his attack on the incumbent's performance on these major issues and his exacerbating widespread discontent on other matters. But after presiding over the government for four years, such campaigning is not credible--as Jimmy Carter found out. So incumbent Reagan is out to accentuate the positive, even if it makes him sound more like his opponents than many of his admirers would like.