It was 1960 and 20-year-old Randy Pennington gladly licked stamps, thumbed them onto envelopes and walked door-to door in Houston, all to help elect John F. Kennedy President.

Last week there was Pennington at Intercontinental Airport in the service of yet another political cause, picking up the candidate and driving him to the $125-a-plate dinner where Pennington had bought a table for eight. The candidate this time, though, was Ronald Reagan.

In between the canvassing and the chauffeuring, a lot had happened in the life of Roland Randolph Pennington Jr. Mostly, he had turned $670 in profit-sharing from his former employer into a $12 million-a-year petrochemical valve business. His net worth now: $2 million.

And somewhere along the way the promises of government and great societies lost their authenticity to him: "The period of 1969 to 1970 speaks for itself. "It sounded like Camelot and brought us to a junk heap." The schools are worse, the dollars are cheaper, the debt is bigger the nation is weaker, morality is lesser.

Add it up and that is the conservative summation, one of apparently growing appeal across the United States. The polls record increasing numbers of Americans identifying themselves as conservative and Republicans have defeated Democrats in three of the four special congressional elections since last November. Thus heartened, the conservative movement turns toward next year's congressional elections and beyond that to 1980.

In that turn Texas is a pivot. For here Ronald Reagan trounced President Ford in the 1976 Republican primary. Here, the former California governor was cheered by 700 diners the other night, Randy Pennington among them. His messages of a dark present and a potentially bright future are well received.

Here too, John B. Connally, the state's former Democratic governor who turned Republican and became Treasury Secretary under Richard Nixon, has started a $1 million political action fund to finance his travels and to channel money to Republican candidates next year.

And here, too George Bush, the former Central Intelligence Agency director, former U.S. representative to China and former Republican national chairman, prepares for a possible presidential race of his own. Anne Armstrong, former ambassador to Great Britain and Cabinet-level adviser to Nixon and Ford is rumored as a potential for the vice presidential nomination in 1980.

Such it is that a state that has elected but one Republican in a statewide election in its history. Sen. John G. Tower, that national ambitions run deep. The only likely explanation offered by political participants here is that if you can't win as a Republican in Texas, go national.

Not that being conservative is the same as being a Republican. (Several people noticed that among Reagan's supporters were faces normally seen at Democratic functions.) Those cheering him on were, judging from a series of interviews, united in their allegiance to common values.

"These are normal Americans active in politics with feelings shared by other normal Americans not active in politics - that is the only difference" said J.C. Helms, 36, a Houston real estate developer with a PhD in classics from Harvard.

"These people don't believe in keepin someone out. They believe in doors open to everyone and then every man for himself . . . the able-bodied and able-minded ought to take care of themselves."

There are puffs of his cigars. "They have a feeling government is too big - let us take care of ourselves. They believe in a strong national defense and have a definite feeling morality has declined. I share those feelings."

O.J. Streigler, 34, also in real estate: "There is no incentive when everyone is given a full mouth. You can have socialism or captialism. You can have an elected democracy or communism."

The views are expressed only a bit less eloquently than those of the men they came to hear. "Weare part of a great body of Americans . . . to personally and individually be free . . . how fed up the American citizen is with the vast federal bureaucracy that interferes with their lives . . . government has already done too much about our problems . . ."

But if the views are limned with less luster, they are as fervently held, and, in a longer interview. Randy Pennington expressed what is on his mind which, he said, is no different from what is on the minds of most Americans.

Through his beliefs runs a strong desire to end the government growth that is viewed as threatening the system that has been so good to so many people. It is system that allowed Pennington, the son of middle-class parents, to be born in Canton, Miss., grow up in Houston and, though nine credit hours short of a college degree, work long and hard to become the sole owner of Control Specialties.

"I knew what I wanted as a young man," he said. "None of that's changed. The promises of the Democratic Party turned out to be a lie. Look how expensive it's been to petuate those broken promises."

The promise was to make life better, he said, and the result has been the opposite. He refers to the secretaries whose salaries have risen steadily across the 11-year span of Control Specialties and add: "We gave them a dollar and took away the value and that's deceitful."

Now, he says, it is time to let the marketplace make life better, to allow people "to become part of the system and reap the rewards of it. [Welfare and government] have robbed people of the dignity of accomplishment. We should let the marketplace take its own course and use a minimum of social legislation to ease the impact on any victims.

"I think we can work it out. We don't need Big Brother to work it out for us. That is a lie, the cruelest of all lies. Bureaucrats just help bureaucrats.

"I am a conservative, someone who wants to preserve the best of what we have."

But what about those whom the system and the marketplace have left out, left behind or left alone?

Pennington says he is not talking about a return to the roaring '20s, about a totally free marketplace. "I think some social legislation was necessary," he said. "In recent years those who want to participate have had an equal opportunity in jobs, schools and living." The problem with minority groups today, he said, is their leaders, "who want to perpetuate their own selfish interests.

"It's just time that we quite saying you owe me something and I'm going to take something from you because of the pigment of my skin," he said.

Pennington says he could not be concerned for the future that his 11-year-old son will have to live in without being concerned for the air and the water, as well as opportunity and the value of the dollar.

Pennington says he still has deep respect for the late President for whose cause he once worked, and he denounces the Johnson era social programs passed in John Kennedy's name.

But what finally moved him to be a politically active conservative was not right-wing propagana or political exhortations , he says. It was instead his tax returns, his bank account, the profits of his own business, and "the piles and piles of paperwork I fill out for the federal government ."

"It is not enough anymore for to us sit around and complain about how things are," said Pennington. "We can change it."