Sen. S. I. Hayakawa (R-Calif) last night urged that the United States "lift the lid entirely on our immigration laws" to take in refugees from Vietnam and other Communist-ruled countries in Southeast Asia.

Speaking at a conference on Indochinese refugees at George Mason University in Fairfax County, Hayakawa said the refugees are "fleeing some of the most despicable atrocities since Hitler's slaughter of the Jews." s

"If we do this charitable, humane thing, we will once and for all show up the present government of Vietnam as the totalitarian, racist tyranny that it is," Hayakawa said."Morally, we shall have won the Vietnam war."

Earlier in the conference, several speakers described resentment toward the Vietnamese refugees, particularly on the part of low-income Mexican-Americans and blacks, who fear the refugees are taking away welfare benefits and jobs.

But Hayakawa declared: "We have an enormous shortage of labor in this country. We have an enormous capacity to absorb people who are willing to work. We have too many people who don't want to work. . . We as a nation of abundance have a duty to share it with people who are willing to work and carry their own weight."

According to State Department figures, about 71,000 Indochinese refugees have entered the United States this year, by far the largest number since 1975 when 133,000 came following the fall of Saigon to the communists.