TO HEAR THE reaction from some conservatives to President Bush's nomination of Harriet Miers to the Supreme Court, you would think the president had named an avowed liberal. The White House has spent the past few days trying to soothe a Republican base angered by the nomination. While there is no reason to doubt Ms. Miers's conservatism, she lacks a long public track record of commitment to conservative causes; she is not among a select group of conservative judicial luminaries; and, though she is reported to be opposed to abortion, she has not staked out a public position on the constitutional issues surrounding Roe v. Wade.

Questions about Ms. Miers's qualifications are legitimate. Her background is not an obvious fit for the Supreme Court, and her especially close relationship with the president raises a fear of cronyism. She will have to convince senators at her hearings that she is excellent and independent enough to warrant a seat on the nation's highest court.

But the rush to judgment is wrong and unfair. There have been a lot of snap judgments and demeaning rhetoric: "Souter in a skirt" is only the beginning. Manuel Miranda, on behalf of a coalition of conservative groups, described her as "possibly the most unqualified choice since Abe Fortas" -- even while reserving judgment. But Ms. Miers's professional accomplishments are not trivial and should not be dismissed simply because she did not go to an elite law school or serve on the bench.

More fundamental is that it is no more legitimate for conservatives than for liberals to demand satisfaction on the "key issues of the day," as Sen. Sam Brownback (R-Kan.) put it. Mr. Bush is not obligated to nominate a jurist with a stated philosophy that can be relied on to produce predictable votes on contested questions. The president promised during his campaigns to nominate justices who would interpret the law strictly and not legislate from the bench. He believes Ms. Miers would be such a justice and is willing to put his prestige behind the proposition, and that fact entitles the nominee to reasonable consideration.

If -- after that takes place, conservatives -- or anyone else, for that matter -- believe her unfit, they have every right to oppose her. But it is no more Ms. Miers's job to promise Mr. Brownback her vote to overturn Roe than it was Chief Justice John G. Roberts Jr.'s job to promise Sen. Dianne Feinstein (D-Calif.) his vote to sustain it. Not even the president's allies are entitled to certainty.