Ronald Reagan, our anecdotal president, has been giving multiple performances of late. Every day, it seems, he is out on the stump. He preaches the simple verities, quotes poetry, cracks jokes, summons the faithful.

Studiedly casual though his appearances are, there is nothing happenstance about them. They are deadly serious and scheduled for a critical purpose. He is in trouble and is running for his political life.

Polls show him sinking in public esteem. Unemployment and bankruptcies are rising. Hopes for quick improvement diminish. Time fades for meaningful policy changes before Congress sets aside everything else for the crucial fall election period. Already on Capitol Hill, some Republicans talk about putting distance between themselves and the president. In the face of such problems, Reagan responds with a flurry of campaign activity that sets the stage for the defense of his presidency.

"The issues are with us this year," he says. "And Nov. 2, if we do our job well, the voters will be in a mood to reconfirm the mandate they gave us in 1980."

The mood he tries to create involves something more than recapturing the winning combinations of 1980. He appeals to the past. In the midst of complexity, he offers simplicity.

Not since Calvin Coolidge, that Puritan in the White House, has a president so earnestly delivered homely little sermons about the rewards of frugality and free enterprise. They sound as if they come straight from the pages of "Poor Richard's Almanack" or Sinclair Lewis' "Main Street," that celebrated novel about local boosterism and small-town life and thought in the 1920s.

The question is, how relevant are they to the realities of the 1980s? Obviously, Reagan believes they are. He stakes his political future on that belief and fervently sends forth his message day after day, as you can see by examining his words in just the last three weeks of public appearances.

"True wealth comes from the heart," he tells the U.S. Chamber of Commerce, and adds: "Entrepreneurs are the heroes of modern times. They rarely receive the credit they deserve."

He extols "the magic of the marketplace," recalls a 19th century James Russell Lowell poem about Columbus' "momentous voyage across the Atlantic," and quotes, approvingly, a burst of jingoistic bombast from Henry R. Luce uttered a generation ago that must now make some in Time Inc.'s hierarchy cringe:

"We're the country of the endless frontier, of the Big Sky, of Manifest Destiny, of unlimited resources, of 'Go West, young man,' of opportunity for all, of rags to riches, mass production, 'nothing to fear but fear itself,' technical know-how, 'a chicken in every pot,' gung-ho and can-do."

The president couples such exhortations with appeals for volunteerism.

He asks citizens "to join with us to determine where need exists and then organize community volunteer groups to meet those needs." To business groups, he explains how his newly created Task Force on Private Sector Initiatives will work. But, lest they be alarmed about just what he expects of them, he reassuringly says:

"We aren't asking you to take over the social welfare system. We're just asking that you give generously of your time, your know-how and your imagination to help Americans help themselves."

In the same spirit, he asks banks voluntarily to lower interest rates and recites a story about the Boy Scouts as proving the merit of his voluntary approach to national problems.

Just think if the Scouts were run by government instead of as a voluntary organization, he says. They would be nowhere as efficient. He even offers a mythical dollar comparison to make his case: If the Scouts were run by the government, doing exactly the same things in the same way as at present, "It would cost about $5 1/2 billion a Haynes Johnson SERMONS --year. And yet as an efficient, nongovernment activity, scouting costs a total of only $187 million a year."

Along with such comparisons, he sounds a call for renewed fellowship and faith. "I believe standing up for America also means standing up for the God who has so blessed this land," he says. Then, more sternly, like some evangelist, he warns: "We've strayed too far. It may be later than we think. There's a hunger in our land to see traditional values reflected in public policy again."

Beyond these themes, though, lies the heart of his message: the evils of government and the blessings of private enterprise.

He speaks scornfully about "government elites and public programs," attacks the "long night of government blundering," praises the people of Barbados where he vacationed by saying "I am convinced . . . they haven't been spoiled by as much welfare as we have in our country" and disparages people in California "who prefer surfboarding to working," singles out for blanket condemnation "an upper middle-class level of bureaucrats who had to maintain those needy people in their needy state as a clientele to preserve their own new-found wealth."

To those who say his economic program unnecessarily hurts citizens in greatest need, he replies, "I don't think any of us lack compassion for the needy, but isn't it time that we also had compassion for those unsung heroes who work and pay their bills while they struggle to make ends meet?"

And, "This administration believes the workers, savers, investors and entrepreneurs of America have been milked and shot at enough."

Reagan's hard political edge comes from his attempt to portray his opponents as the agents of society's ills, accumulated over decades. They are the big spenders. Those who differ with him want to go back "to the glory days of big, never-mind-the-cost government."

His special target, singled out again and again, is House Speaker Thomas P. (Tip) O'Neill Jr.

He casts O'Neill as the scapegoat. O'Neill is to blame for failure to reach a compromise on his budget (which his own party rejected on Capitol Hill). When he met with the speaker, he says, "There was no give whatsoever, even a suggestion or hint of negotiating. And this is why the meeting ended with nothing accomplished." Philosophically, he adds, O'Neill believes that "you don't cut the budget. And somewhere the deficit just seems to be invisible where he's concerned. He doesn't think that counts."

Reagan takes no responsibility for the deficits in his budget, shaped during his tenure as president. He rejects the idea his economic program has anything to do with the present recession and unemployment. "I certainly won't accept the idea that a program which began after the recession was already under way is somehow responsible for that recession," he says.

These, of course, are debating points, but there's no debate about the real thrust of his message. It is purely ideological. He believes government should do as little as possible. The free marketplace will take care of all our problems. Follow his lead and all will be well.

"Our economic program will try to help everyone," he says. "It will encourage wealthier Americans to stop seeking tax shelters and invest in productive industries and businesses that will produce new jobs and greater wealth for all of us."

Since we now know that one of his closest friends and aides, Attorney General William French Smith, has profited grandly by putting his wealth to splendid advantage in tax shelters, perhaps the president would like to rephrase that one now. But surely his basic message would remain the same.

Like one of old Ben Franklin's maxims, it's quite simple. In the 1980s no less than the 1700s, the Lord helps those who help themselves.