Clare Boothe Luce has done it all: elective politics, publishing, writing, diplomacy, grand damery and perennial public service.

She has been a member of Congress (first elected in 1942), an ambassador to Italy, an author of plays and novels, wife of the founder of Time and Life, adviser to presidents.

Now, at age 79, she seems intent on taking up a new pursuit: bigotry. Not the cross-burning, synagogue-trashing sort of bigotry. Hers is the intolerance of a great American lady who worries that outsiders are ruining her country.

"Soon," she told Milton Benjamin in an interview for GEO Magazine, "there will probably be as many Mexicans in Texas, New Mexico, lower California and Arizona -- and as many Cubans and Latin Americans in Florida -- as there are natives. They are also pouring in from Haiti. Now, a vast majority of these are illegal. They're coming over the border, and they're coming in with wives and sisters and nieces who get pregnant immediately because they can then become American citizens and go on relief. I do not know how much more we can absorb."

Well, now isn't than an interesting comment for someone with a sense of history who knows that America is, if it is anything, a nation of immigrants?

"Sure," she acknowledges. "In the 19th century, the United States absorbed something like 40 million immigrants. But the vast majority of them were of a fundamental culture, and they were all white. They were not black or brown or yellow."

So that's it. America's great fortune is that it is a nation of white immigrants. We're getting too many of the wrong kind these days, and don't let anyone kid you about the positive value of melting pots and cultural diversity.

"Today," says Luce, "we have this curious idea that we must tolerate to the maximum all the diversities. I am not sure we are not heading for the fate of ancient Rome, which in its later days had far fewer Romans than immigrants from all the conquered provinces around the Mediterranean basin. Rome became a city of pollution and noise and foreigners, and it collapsed under the weight of the barbarians. But in truth Rome collapsed because the people within lost all desire to coalesce and defend it. It just fell apart."

We've been misled. It wasn't the orgies that did Rome in; it was excessive tolerance. Luce has had it up to here with tolerance.

Also with compassion.

"Americans identify with America, and increasingly there are people -- Poles, Italians, Israelis -- who identify with two countries. But I do not know of any other identification that I can make, say, with the condition of the people of the Sahara. I repeatedly see pictures in the papers of a starving mother with her child holding out its hand. I think it would be hypocritical if I didn't say that I would feel a little more compassion if one of my pet birds had broken a leg in its cage in my own house."

Luce's remarks are the more remarkable because she is not an empty-headed woman. Indeed, much of what she has to say on other subjects covered in the airborne interview with Benjamin is the stuff of useful debate. The nuclear arms race: "I believe we now have enough weapons for all possible purposes of destruction." Ideological competition: "Three quarters of the nations of the world are not culturally adapted to democracy." Foreign commitments: "(The president) has to commit himself at the global level to a series of purposes and goals for which we do not have the military power."

But these interesting, if controversial, notions are sure to get lost in the wash of her genteel bigotry, which Raul Yzaguirre, president of the National Council of La Raza, has called "a grave insult to all immigrants of color in this nation."

He has asked President Reagan to remove Luce as a member of his Foreign Intelligence Advisory Board and as special adviser to William Clark. Otherwise, Yzaguirre warns, Reagan will be construed as condoning the utterances of the incredible Luce lips.