In a speech to graduates of North Carolina A&T, Jesse Jackson, class of '64, encouraged the students to battle the odds, as he had done. He told of being ''born of a teen-age mother . . . a teen-age mother who never really had a chance.''

A decade ago, when working in Chicago as head of People United to Save Humanity, Jackson was also publicly and regularly referring to his mother. ''I was born out of wedlock,'' he wrote, ''and against the advice that my mother received from her doctor.''

Two Jacksons are on view. In the 1970s, accounts of his mother and his birth were used to support the Baptist minister's arguments opposing abortion. Today, as a Democrat running for president, Jackson has reversed himself. His tales of mother delete allusions to abortion. He supports federal funding of abortion and says moral positions shouldn't be imposed on public policy. Freedom of choice must prevail. He echoes the arguments that make Democrats the party of abortion.

No other candidate this season, fallen or still standing, has shifted positions as radically as Jackson on abortion. Nor has any reversal received less attention.

In January 1977, Jackson wrote a 1,000-word essay for the National Right to Life News. It was one of his many statements on the issue, including an ''Open Letter to Congress'' in which ''as a matter of conscience I must oppose the use of federal funds for a policy of killing infants.'' He spoke at the 1977 March for Life and asked, ''What happens . . . to the moral fabric of a nation that accepts the aborting of the life of a baby without a pang of conscience.''

More than the letter and the speech, the essay was a comprehensive examination of abortion, ranging from moral to political questions. It was widely circulated by opponents of abortion because 10 years ago they were unfairly portrayed as single-issue right-wing fanatics. A few were, but here was Jackson, far left and multi-issue. The essay had intellectual power, written with the clarity and succinctness that remain much of Jackson's vote-getting appeal today.

Identifying himself as a person who would have been aborted if medical counsel had been followed, Jackson wrote that ''in the abortion debate, one of the crucial questions is when does life begin. Anything growing is living. Therefore human life begins when the sperm and egg join . . . and the pulsation of life takes place. From that point, life may be described differently (as an egg, embryo, fetus, baby, child, teen-ager, adult), but the essence is the same.''

Now, as then, abortions are legal at 24 weeks. Unlike in 1977, neonatal care can save the lives of 24-week-old babies. If Jackson had not reversed his position, he would seize on that fact and add it to the blunt but accurate language he was using in 1977: ''Those advocates of taking life prior to birth do not call it killing or murder, they call it abortion. They further never talk about aborting a baby because that would imply something human. Rather, they talk about aborting the fetus. Fetus sounds less than human and therefore can be justified.''

If Jesse Jackson of the 1970s were to debate the Jesse Jackson of 1988 on abortion, the old would flatten the new and leave him mumbling pro-choice slogans. As Jackson now does: ''Women must have freedom of choice over what to do over their bodies.'' The 1977 Jackson would repeat his still-sound conviction: ''Some argue, suppose the woman does not want to have the baby. They say the very fact that she does not want the baby means that the psychological damage to the child is enough to abort the baby. I disagree. The solution to that problem is not to kill the innocent baby but to deal with her values and her attitude toward life -- that which has allowed her not to want the baby.''

Jackson of 1988 says abortion is acceptable because ''it is not right to impose private, religious and moral positions on public policy.'' The 1977 Jackson handily dismissed the privacy argument: ''If one accepts the position that life is private, and therefore you have the right to do with it as you please, one must also accept the conclusion of that logic. That was the premise of slavery. You could not protest the existence or treatment of slaves on the plantation because that was private and therefore outside your right to be concerned.''

None of Jackson's six Democratic opponents made an issue of his desertions. Perhaps they saw him ''maturing,'' which is said of Jackson's '88 campaign. A pro-abortion party can embrace Jackson, but it is getting a defective product. Jackson has become the kind of politician he warned about a decade ago, one whose pro-abortion arguments ''take precedence over human value and human life.'' Or as the word master could say: Don't agonize, compromise.