No one can confuse Sen. Mark Hatfield of Oregon with his Republican colleagues Jesse Helms (N.C.) and Orrin Hatch (Utah). Hatfield is a reflective liberal whose responses to issues are touched with moral sensibilities. Whether supporting the nuclear freeze or opposing capital punishment, he is far removed from the right-wing grossness that Helms' thinking represents. Intellectually, he is well above the superfluity of Hatch.

But on one issue--abortion--Hatfield thinks like Helms and Hatch. The three have separate anti-abortion bills pending in the Senate. Like Helms and Hatch, Hatfield doesn't want the federal government to "kill innocent human beings or assist others to do so through federal abortion funding."

In April, Hatfield introduced the "Federal Abortion Funding Restrictions Bill." Unlike the Helms legislation, it does not attempt to define when life begins. Unlike Hatch's bill, it does not seek to alter the Constitution with an amendment. Instead, Hatfield is calling his bill "a meaningful beginning" toward the goal of getting the government out of the abortion business. The bill, finding that "unborn children who are subjected to abortion are living members of the human species," would "affirm for the first time that Congress recognizes the value of all human life."

Abortion rights advocates have had a rompingly easy time opposing Helms and Hatch. The hypocrisy factor comes into play, especially with Helms. His record shows little concern for humane solutions to social problems. Through his attacks on the food stamp program, he has picked on one of the nation's most powerless groups, the hungry poor. His championing of the rights of the fetus, while denying so many rights of the born, sets him up for the contempt that his double standard deserves.

It is not much different with Ronald Reagan, who also opposes abortion. The line that ridicules his policy has become familiar: "The Reagan administration believes that life begins at conception and ends at birth."

Hatfield may be ending this free ride for abortion advocates. He is pro-life on abortion and his record on issues such as weapons funding, food stamps, corporate ethics, ecology and racism is consistently pro-life as well. Liberals can't attack Hatfield's opposition to abortion the way they can Helms' or Reagan's.

He can't be accused of selectivity. Hatfield believes that life begins at conception and ought to be protected until death--protected against governments with nuclear bombs, corporations that desecrate the environment, budget directors who want to cut funding for poverty programs, and abortion advocates who, for reasons noble or base, want to destroy life.

Hatfield's leadership role on this issue, though late, separates him from other liberals in Congress who have taken the "I'm personally opposed but. . . ." dodge. Hatfield is personally opposed to abortion and now, to his credit, he is legislatively opposed. Rather than being a "single-issue" opponent of abortion, Hatfield is a single- standard opponent. He says, "It is because of my ethical commitment to life-enhancing measures, whether a nuclear freeze initiative or meeting the needs of our elderly poor, that I am introducing this bill."

Groups such as the National Abortion Rights Action League have been unsettled by Hatfield's emergence. NARAL's executive director, Nanette Falkenberg, says, "We're extremely concerned because his bill is being misperceived as a moderate piece of legislation. The impact is just as harmful as the Helms legislation."

An official of the Reproductive Freedom Project of the American Civil Liberties Union charges that the Hatfield bill "seeks to accomplish by stealth what the Helms human life bill sought to accomplish directly, the overturning of the right to choose abortion."

The attacks don't hold. Linking Hatfield with Helms is close to a smear. Hatfield has never dealt in stealth and he isn't now. Abortion advocates can no longer rely on worn-out slogans to defend the rationalized violence of abortion. They can't depict Hatfield as a loony who screams "baby killer" at his opponents.

Instead they are faced with a sophisticated progressive who correctly sees abortion, along with war, capital punishment and social budget cuts, as one more denial of the right to life.