The American public continues to support legalized abortion by a wide margin, and more than two of every three Americans oppose any law that would make abortion murder, according to a new Washington Post-ABC News Poll.

The nationwide poll indicates that abortion has become a pervasive fact of life in modern America, tolerated by a large majority of the public, although often reluctantly and with mixed emotions.

More than half of those surveyed said they know a woman who has had an abortion; 40 percent say they know at least two women who had had one.

One woman in 14 said she has had an abortion -- a figure many consider low in a society where one pregnancy in three is said to end in abortion. The group of women who have had abortions includes liberals and conservatives, Replublicans and Democrats, those who favor legalized abortion and those who oppose it.

According to the poll, 40 percent of Americans approve of abortion on demand and an additional 34 percent approve of it in most circumstances; 16 percent disapprove of abortions in most circumstances and 10 percent would like to make all abortions illegal.

The public has little confidence that a ban on abortions would work. Almost three-fourths of those surveyed say that if such a law were enacted, a woman wanting an abortion would still find a way to get one.

Yet few issues cause as much anxiety and conflicting emotions among individuals. Despite the widespread approval of abortion in principle, Americans find it much harder to accept abortion when it touches their lives. Among those who know a woman who has had an abortion, almost half said it was improper for her to have done so.

And when asked what advice they would give if they had an unmarried, pregnant 15-year old daughter, only one adult in four said they would recommend she have an abortion.

Much of the uneasiness clearly results from deeply held moral and religious beliefs coupled with a widespread sense of moral decay in the nation. The more a person expresses a deep religious sentiment -- regardless of the religion -- the more likely that person is to oppose abortion on demand.

Two-thirds of Americans interviewed in the Post-ABC poll feel more permissive attitudes toward sex in recent decades have been bad for the nation. p"The changes brought about in the last 20 years have centered on individualism," said one 45-year-old union official from Los Angeles. "We've become concerned with finding ourselves, and lost concern for others."

A 34-year-old father from an Atlanta suburb was more direct: "I think we're all for pleasure-seeking and hedonism. No goals. No aims. No beliefs. Just self-gratification."

Half of those surveyed feel legalized abortion has contributed to this decay by encouraging sexual promiscuity. A 21-year-old Mormon woman from Arizona with a young child gave an emotionl personal testimonial on this.

Teen-agers have become freer about sex because abortions are available, she said. "Too many teen-agers are having sex. Girls are getting pregnant way too young. It's ruined their lives. I'm one of them. . . ."

This feeling is far from universal, however. Americans are basically tolerant and pragmatic people, and a strong live-and-let-live strain appears throughout the Post-ABC poll -- a sentiment that allows people to oppose abortion personally but tolerate it for others.

That personal-choice sentiment apparently extends to subjects other than abortion. A few examples: 67 percent of those surveyed say birth control devices should be made available to teen-agers, and 39 percent say homosexual relations between consenting adults should be legal. Citizens split almost equally on whether or not lesbians and homosexuals should be alloweed to teach in public schools.

Among those surveyed, 88 percent favor legal abortions when the woman's life is endangered; 82 percent in cases of rape or incest; 84 percent when the woman might suffer severe health damage; 70 percent when there is a chance the baby would be born deformed, and 73 percent when a woman's mental health is endangered.

What Americans don't easily accept is abortion for economic reasons. Only 47 percent in the poll say that abortions should be legal for families who can't afford to have the child.Support for federal financing of abortions for the poor is also weak; 40 percent of those surveyed favor it and 54 percent oppose it.

A total of 1,533 persons were inerviewed by telephone in the Post-ABC poll from May 18 to 20.

Activists on both sides of the abortion issue who were contacted by The Post found parts of the poll to boost their cause. The Human Life Bill, which the Senate has recently been holding hearings on is a good case in point. The bill would attempt to outlaw abortion by defining life as beginning at conception, thus making the unborn fetus eligible for protection of due process of law under the 14th Amendment.

The poll approached the bill in two ways. First, it asked, "At what point do you think a fetus becomes a human being?"

The results favored abortion foes: 41 percent said at conception, when sperm meetings egg; 30 percent said during the first three months of pregnacy, 12 percent said during the last six months of pregnancy; 11 percent at the time of birth. Six percent had no opinion.

This led anti-abortionists to claim public support for the bill. Pro-abortionists, however, claimed a second question showed overwhelming opposition to the same bill.

That question: "Would you favor or oppose a law that would make all abortions murder?" Only 29 percent of those polled favored such a law; 67 percent opposed it.

The question, however, was controversial. Spokesmen for the National Abortion Rights Action League (NARAL), a pro-abortion group, approved of the question. But Sen. John P. East (R-N.C.) and other anti-abortionists claimed the question distored the bill. The proposal, they said, is not a criminal statute.

The poll results indicate that the anti-abortionists are far better known than their opponents. Asked if "you have read or heard anything about the Right to Life group," 71 percent of those surveyed said yes. Half of this group said they agreed with goals of the group.

Only one-fourth of those polled had heard of organized pro-choice groups, or those favoring legalized abortion. RARAL executive director Karen Mulhauser attributed this to the fact that anti-abortionist have been far better financied and have had the help of existing institutions in furthering their cause.

"They've had access to the electronic church and the hierarchy of the Catholic church," she said. "They've reached a lot of people through institutions we don't have access to."

Electronic ministers may be much more popular than is generally suspected. Of those polled, 29 percent say they regularly watch or listen to preachers on television or radio. By comparison, 44 percent say they attend religious services almost every week.

The Post-ABC poll indicates that abortion is an issue that cuts across political, age, class, regional and religious lines. A sizable number of conservatives and liberals, Republicans and Democrats, are found on both sides of the issue. The great majority of Protestants, Catholices, Jews and unchurched favor legalized abortion in one form or another.

But anti-abortionists find their greatest strength among highly religious conservatives with high school educations. Sixty percent of the hardcore anti-abortionists consider themselves conservatives; 14 percetn liberals. One-third of those who generally support abortion consider themselves liberals, 29 percent conservatives.

There also are clear value and morality difference between those who support and oppose abortion.

Hard-core abortion opponents over whelmingly oppose the Equal Rights Amendment, believe life begins at conception, and feel changes in sexual life styles have been bad for the country. Four of every five oppose the sale pornography and homosexual relations between consenting adults; only 4 percent think the sale of marijuana should be legal -- a position favored by 26 percent of those who favor abortion.

Anti-abortionists are slightly more likely to live in the Midwest, watch television ministers and belong to the Republican Party.

The politics of abortion are intriguing. Americans are almost equally divided over whether a political candidate's position on the issue is important, the poll indicates.

Seven percent of the respondents said they have voted for or against a candidate becauise of his position on abortion.

Mulhauser said this substantiates her long-held belief that antibortionists have overstated their political strength.

"They have created the perception that anti-abortion people are strong enough to defeat politicians who oppose them," she said. "That perception isn't substantiated by this or other polls on the issue."

However, East, who has chaired recent hearings on the Human Life Bill, notes he beat former senator Robert Morgan last fall by only 11,000 votes. "Seven percent is certainly enough to make a difference in a close election," he said. "Abortion per se wasn't a major issue in our race, but Morgan had some problems with the issue. He ended up having a rather high negative among right-to-lifers."

"I won by 11,000 votes. All things are possible in that kind of situation," he adds. "It could have made the difference."