SEN. GEORGE McGOVERN is right, of course in saying that President Carter has gone to remarkable lengths to soothe the last election's losers. The President's solicitude for the businessmen is extraordinary. But Sen. McGovern - to judge from his speech this weekend to the Americans for Democratic Action - doesn't know why it's happening and doesn't much care. It's that old familiar note of willful innocence in the senator's clarion calls, the habit of arriving at a shining answer by the simple device of excluding the rough parts of the question.

True, the President tends to run too far after that will-'o-the-wisp, business confidence. But his basic strategy is a rational and substantial one that deserves to be debated on its own terms. Sen. McGovern wonders why we can't somehow recapture the magic of 1961, when the Democrats swept into power and lo, there was a great boom for years. But economists of all denominations have learned a couple of interesting things since 1961.

First, they know conclusively that inflation generates unemployment. It's not just a matter of callously tolerating high unemployment to please the bankers. It's a recognition that no government can do much about the unemployment rate as long as prices keep sliding rapidly upward. Second, everybody now knows that a radical rise in a basic commodity - oil, for example - can actually happen, with a severe impact on jobs in the United States.

That's why Mr. Carter gives great attention to inflation and tries diligently to soft-soap the businessme into cooperating. That's also why he has put the energy program ahead of welfare reform and health insurance. You can quarrel with the President over the way he does these things. But you can't merely ignore his reasons for doing them and pretend that they don't exist.