President Carter is entering the 1980 presidential campaign with an unusual platform for an incumbent Democratic politician:

Despite the prospect of recession -- with the jobless rate apt to rise to 7 1/2 percent by November -- he is not proposing any new economic stimulus. Instead, he is expected to call for continuation of his earlier moderate restraint.

Although inflation is eroding real income and pushing taxpayers into higher brackets, Carter will eschew any new tax cut. As a result, voters will go to the polls with a decided cut in their purchasing power.

Though the first primary is next month, the president deliberately is not proposing any large new social initiatives. Instead, his new budget will squeeze some domestic programs to make room for added increases in defense.

For all his earlier campaign talk about the need for low interest rates, Carter is endorsing tight money policies by the Federal Reserve Board that have pushed interest rates up to nearly double their 1976 levels.

Is this a recipe for election-year success?

That question may not be answered until the polls close on Nov. 4, but in truth Carter has virtually no choice in the matter.

Continued inflation, combined with a increased threats to the dollar from the Iranian situation and the energy shortage, effectively have boxed the president in and prevented any new moves on the domestic front.

Carter also feels reluctant to propose any new energy measures. Policy makers had been toying earlier with the notion of a 50-cent-a-gallon gasoline tax or a mild form of rationing to help reduce consumption.

But this, too, has been put on the shelf.

To be sure, there are some arguable economic reasons for the president's decision this time:

Both conservatives and liberal economists fear that cutting taxes now might overstimulate the economy -- as it has in previous years -- and only fuel inflation further.

More forecasts still are so uncertain that economists are cautioning the administration to wait before acting for sure signs that the recession really is here. That may take until late spring, yet the budget deadline is here.

Most analysts say the most effective step the president could take to help dampen inflationary psychology is to balance the federal budget -- or at least reduce the size of this year's $30 billion deficit.

Carter's new budget, which will top $615 billion, is slated to show a deficit of $15 billion, about half the current year's figure. Except for defense and a new youth jobs program, most programs are just keeping pace.

If Carter were to abandon his fiscal austerity theme, it probably would spark another slide in the dollar on the foreign exchange markets -- adding further to inflation here at home.

Whatever the actual justification for the markets' behavior, the risk is serious enough to give any administration pause before setting off another dollar slide. A serious dollar slump would itself add to inflation.

The question is, will cautious economics make good politics in an election year -- particularly one that is likely to see a recession? And will party loyalists be satisfied with nothing to give away before November's vote?

For the moment, at least, the answer seems to be yes -- in part because the electorate appears to be more concerned about combatting inflation than coping with any coming recession.

Carter has more flexibility than is typical in an election year in part because most Americans still aren't blaming him for the nation's economic problems. They see the oil cartel and Congress as major villains.

Moreover, for all Carter's tough-sounding austerity talk, the $615 billion budget he is proposing later this month is not expected to cut seriously into traditional Democratic domestic programs, as the White House had hinted.

For one thing, most major domestic programs are expected to keep up with inflation. And Carter budget makers, mindful of election-year political needs, added in a few sweeteners just before the final figure was set.

For example, despite earlier complaining that is was unnecessary, Carter agreed in the end to continue the state's share of the $6.9 billion general revenue-sharing program, and also put back monies for some job programs.

Taken together, these restorations don't add up to much. And Carter has only one new initiative -- the new youth unemployment program. But the strategy has mollified that more outspoken constituent groups.

Confirmation of the political staying power of Carter's approach to a tax cut has been evident in Congress during the pre-budget season.

Most lawmakers surveyed in the past few weeks have said they thoroughly approved of Carter's decision not to propose one. And the majority applauds the absence of new spending programs as well.