Supreme Court nominee Brett M. Kavanaugh during his Senate confirmation hearing on Sept. 5. (Saul Loeb/AFP/Getty Images)

AS THE Senate considers his nomination to the Supreme Court, Judge Brett M. Kavanaugh has encountered more turbulence than many previous nominees. Some of this is, no doubt, an interest-group-driven, partisan response to a GOP pick in a fraught time. But, in at least one respect, Republican efforts to rush through Mr. Kavanaugh have prevented a fair weighing of his nomination. The circumstances demand that Mr. Kavanaugh’s confirmation be delayed — and we are not referring to the latest allegations from an unnamed high school acquaintance of Mr. Kavanaugh, the focus of much attention this past week.

Democrats and Republicans typically agree on which documents senators and the public get to review before Supreme Court confirmation hearings begin. In this case, Republicans charged ahead with no such agreement and failed to ask for a huge trove of documents relating to Mr. Kavanaugh’s tenure as staff secretary to President George W. Bush, a job the nominee said deeply informed his judging.

Republicans argue that the staff secretary documents would not be relevant. How do they know? They have not seen them. Undoubtedly, many, perhaps most, of them would not be turned over. But there is no pressing reason Mr. Kavanaugh’s nomination must be considered before Republicans’ artificial October deadline. A nonpartisan entity, perhaps the National Archives, should sort through the staff secretary documents. Voting should be postponed until a fair assessment of the files has been completed and germane documents turned over to the Senate.

On Mr. Kavanaugh’s merits — according to the record presently available, at least — the nominee boasts a distinguished tenure as an appeals court judge and the confidence of a variety of legal luminaries. In his hearings, he rightly endorsed United States v. Nixon, which obligated President Richard M. Nixon to turn over evidence to the Watergate special counsel. He was also quicker to embrace the landmark Brown v. Board of Education desegregation decision than was Justice Neil M. Gorsuch during his confirmation. But Mr. Kavanaugh was more reluctant to criticize President Trump for politicizing the Justice Department. Offering mostly evasive answers, his hearing performance was about as disappointing as that of past successful nominees.

Mr. Kavanaugh bears a special burden, though. He wrote an article a decade ago proposing that presidents should not be investigated while in office. Mr. Trump fumes constantly about the investigation of special counsel Robert S. Mueller III. If Mr. Kavanaugh becomes the fifth vote in a Mueller v. Trump case, many Americans would question whether the president picked him for the express purpose of protecting the White House from a valid criminal investigation, and whether Mr. Kavanaugh followed script. Suspicions would corrode the court’s credibility.

Mr. Kavanaugh responded that he needed to be careful answering questions about what he would do if such a case came up, explaining that making any commitments would harm judicial independence. Yet he could have offered more assurance without making a direct commitment, as he did on other topics.

If the process for considering Mr. Kavanaugh were complete, this lapse might represent the biggest issue senators would have to weigh. With the rushed process Republicans have imposed, they must also consider whether they want railroading the minority to be the new normal.