Delay is itself a win for Mr. Trump and fits into his broader strategy of trying to avoid oversight and scrutiny — not only by filing this lawsuit but also by resisting other congressional subpoenas and, most recently, speaking out against congressional testimony by Robert Mueller that even Attorney General Bill Barr had publicly accepted.

Whatever the outcome of Mr. Trump’s legal argument, we urge the judge to move on the merits quickly. The issue appears to be straightforward. There are no privileges involved, and Mr. Trump’s major argument seems to be that Congress lacks the authority to investigate him. In our view, the case could be resolved by the district court within weeks, not months. The same rationale applies to the other subpoena litigation that is or will shortly be pending in the district courts, and it applies to Congress’s own efforts to obtain subpoenaed materials and secure witnesses for testimony. “Delay Till After 2020” should not be allowed to thwart legitimate oversight.

If Congress and ultimately the American people are to see Mr. Trump’s financial records, they should see them as soon as possible, as American voters are already considering whether they want to give the president four more years. Moving forward the litigation so that it’s resolved, one way or the other, soon or certainly well ahead of Election Day is a matter of judicial responsibility.

That’s exactly how a federal judge handled the litigation surrounding Mrs. Clinton’s emails in the 2016 campaign. When it emerged that she had used a private email address and server to conduct official business as secretary of state, it became clear that documents previously provided to the public in response to requests for State Department records hadn’t included the privately held emails. Consequently, some people who had made those previous requests went to court demanding that the privately held emails be released — quickly.

The federal judge overseeing the litigation agreed, rejecting the State Department’s proposed timeline for reviewing and releasing the emails and ordering the government to accelerate. He didn’t need to say out loud what everyone knew: Voters were assessing Mrs. Clinton’s fitness for office, and these emails could inform that assessment. It was obvious that the litigation should move swiftly and, in particular, should yield public releases of the emails before Election Day. It was a sense of the undeniable stakes of moving quickly when the litigation had such clear bearing on a coming presidential election.