IT WAS ONLY a few days ago that President Bush was touting Harriet Miers as a pioneering woman whose lack of experience as a judge was a selling point for service on the Supreme Court. Yesterday he responded to the implosion of her nomination with a return to basics: a highly qualified nominee who adds no diversity to the court but whose reputed conservatism greatly excites the president's base -- and greatly offends the opposition party. Indeed, as soon as the White House proposed Judge Samuel Alito's elevation to the Supreme Court, the battle that both sides have been anticipating since the president took office began. Reports and statements praising or denouncing the nominee whizzed around town. Everyone, it seems, had a judgment at the ready. We await a thorough and serious confirmation process before venturing ours.

In conventional terms, Judge Alito -- who sits on the U.S. Court of Appeals for the 3rd Circuit -- is an exceptionally strong nominee. He has been a federal appeals judge since 1990, a qualification that Mr. Bush trumpeted yesterday with no sense of the irony of his having discounted such experience only recently. Before that, Judge Alito was the U.S. attorney in New Jersey and an official at the Justice Department, where he also served a stint in the solicitor general's office. His professional background and experience will not raise any of the anxieties that members of both parties felt about Ms. Miers.

That means that any opposition to his nomination will be on ideological or philosophical grounds. The basis could be disagreement with his methodological approach to cases or, more crudely, with his past or anticipated votes. Unlike all recent conservative nominees to the high court, Judge Alito has a lengthy record of public writing on constitutional and statutory questions. He is neither a stealth nominee nor someone who can plausibly attribute his writings to the interests of clients or dismiss them as old. Rather, he has spent the past 15 years deciding actual cases and explaining his reasoning. In doing so, he has taken conservative positions in cases on everything from abortion to immigration to discrimination to the proper scope of Congress's authority to regulate interstate commerce. For the first time since Robert H. Bork's nomination nearly two decades ago, liberal senators will face the question of how much they have to disagree with a nominee's record before voting no.

One thing that is clear from a cursory review of Judge Alito's work is that he is not a bomb-thrower but rather a judge who is careful -- even in dissent -- to be respectful of his colleagues' work. His opinions probably don't contain the sort of flamboyant statements that can become defining sound bites in a bruising confirmation battle. Evaluating Judge Alito will necessarily be a more subtle project than assessing some of the judges President Bush has nominated to lower courts. As the process moves forward, we hope to see evidence that Judge Alito applies his judicial philosophy even where it produces results that are not favorable to conservatives. We will be looking for evidence of his respect for settled precedent and for signs that he understands that interpreting the Constitution strictly does not mean needlessly constricting language that was intended to be a broad charter for government. Most of all, we'll be looking for evidence that he has an open mind, something senators should try to keep when regarding him.