Robert Mueller will finally be testifying before Congress about his report, and the portrait it paints of a president systematically disregarding the law. In the months since the report’s release, Democrats have not effectively used the levers available to them to investigate President Trump or brought the full scope of his wrongdoing to the attention of the nation. The House needs to reset its investigation after Mueller testifies, taking a page from prior congressional responses to presidential wrongdoing.

Most of the blame for stymieing Congress’s investigative efforts properly resides with Trump and his administration, primarily Attorney General William Barr, who baldly lied about Mueller’s findings and then joined with the White House in defying congressional efforts to obtain access to evidence and witnesses.

Yet it should hardly have come as a surprise to legislators that a president with contempt for the Constitution would defy oversight by a Democratic Congress. And while lawmakers are taking wholly appropriate steps in the courts to enforce their subpoenas, they have yet to otherwise implement an effective and coordinated strategy to respond to Trump’s stonewalling, including by cogently informing the nation about the nature and scope of Trump’s misconduct.

While many critics of Nancy Pelosi and the congressional leadership recognize the seriousness of the problem, the supposed solution they advance falls wide of the mark. Critics’ most frequently heard demand is that the House immediately pass a resolution authorizing a formal impeachment inquiry, as it ultimately did during Watergate. Pelosi refuses to take that step now, and for good reasons. It is opposed by the majority of vulnerable Democratic lawmakers, who recognize that it could harm their chances for reelection, and it is currently inconceivable that Trump would be removed from office by the Senate, even if he was impeached by the House. Accordingly, unless the courts direct that Congress must commence an impeachment proceeding to obtain access to the evidence and witnesses it requires, there is good reason to withhold from taking that step.

“ I scripted it like a story, like a detective story.... ” — Watergate chief counsel Samuel Dash

In any event, Congress’s relative ineffectiveness in holding the president to account to date is not the product of the absence of formal impeachment proceedings, but rather of Congress’s failure to commence a single, focused, fully staffed—and to the extent possible—public investigation directed at bringing the full nature and scope of Mueller’s findings to broader public attention and uncovering other misconduct by Trump and his associates.

Part of the problem is the structure of the House itself. Multiple committees, including judiciary, intelligence, oversight and ways and means, have responsibility for one or more areas of inquiry into presidential misconduct. Furthermore, no single committee has engaged a large, dedicated staff of lawyers and investigators that is singularly directed at gathering evidence, interviewing witnesses and analyzing the facts and the law related to Trump’s misconduct. Absent such a centralized, focused and fully resourced effort, equal to that of the former special counsel’s office, Congress can’t be expected to go toe-to-toe with the DOJ and the White House, and their stonewalling efforts.

Congress has a well-established model for doing just that: establishing and staffing a committee for the sole purpose of investigating the president’s wrongdoing. Both Houses of Congress have formed such special and select committees in a wide variety of contexts, including to investigate the Iran-Contra scandal, Hillary Clinton’s (non-existent) role in the Benghazi incident, political assassinations, CIA misconduct and climate change.

In 1987, the nation watched public joint hearings held by House and Senate select committees established to investigate Iran-Contra. As a result of effective investigation by a staff led by Senate Chief Counsel Arthur Liman, as well as effective questioning by both staff and legislators, the nation learned the facts surrounding a dizzyingly elaborate Reagan administration scheme to evade a congressional bar on funding Nicaraguan right-wing insurgents (and the ransoming of hostages) by selling arms to the Iranian regime.

Watergate provides the preeminent example, and also serves to demonstrate just how beside the point the debate over whether to immediately commence a formal impeachment inquiry actually is. In February 1973, a year before the House Judiciary Committee began its formal impeachment proceedings against Richard Nixon, the Senate established a seven-member select committee, staffed with skilled lawyers and investigators and tasked with comprehensively investigating allegations of wrongdoing by Nixon and his campaign. The committee held weeks of hearings, some 250 hours of which were publicly broadcast.

Even before blockbuster evidence came to the light, Senate investigators evinced an array of misconduct by the Nixon presidential campaign, such as the “dirty tricks” employed against Edmund Muskie and other Democratic candidates. The Senate Committee, and its Chief Counsel Samuel Dash, ultimately publicly disclosed much of the key evidence against Nixon, including through the testimony of White House Counsel John Dean, and revealed the existence of the White House tapes that contained the evidence that would ultimately force the president from office. As Dash later explained, “I scripted it like a story, like a detective story.... The most important thing I had to do was convey the information to the public in a way they could understand.”

By contrast, while critical, much of the House Judiciary Committee’s work largely commenced many months later; additionally, much of its investigative work was conducted in closed session. Also, the final six days of publicly televised hearings, culminating in the committee votes in favor of impeachment, were significant not simply because a majority voted in favor, but because, by that point, the evidence against Nixon had become so overwhelming that substantial numbers of Republicans did so as well, making it clear that the President would not be able to remain in office. Once again, staff work was the key. As attorney Bernard Nussbaum later recounted, the staff’s review of the evidence and carefully organized presentation of it to members of Congress, under the guidance of Special Counsel John Doar, was critical to convincing Republicans to vote in favor of impeachment.

Congress’s past successful investigative efforts thus reinforce the importance of a carefully managed, properly resourced and comprehensive investigation, conducted in public to the full extent possible.

To date, Congress has been frustrated in its efforts to get “star” witnesses from the Mueller Report in the witness chair because of Trump’s position of maximum resistance, and establishing and staffing up an investigative committee won’t change that immediately. But it will allow Congress to focus its litigation and other efforts in a more singular, and therefore likely more effective, way, as it has before.

In addition, it will allow Congress to take a more comprehensive approach, to its investigative efforts, rather than being bounded by findings or theories of Mueller or other law enforcement authorities For example, Jed Shugerman has convincingly argued the evidence Mueller adduced alone could support a number of, as yet, uncharged campaign-finance related offenses against Trump and his associates. Congress should have the resources necessary to fully examine and test these and other theories, and to bring the full scope of Trump’s illegal conduct to the attention of the nation. Also, during a recent oral argument before the D.C. Court of Appeals regarding a subpoena served upon Trump’s accounting firm, Judge Neomi Rao, a Trump appointee, suggested that a specially constituted House committee may have greater authority to demand evidence from the president.

As Lincoln famously observed, “public sentiment is everything.” One cannot predict from the outset what evidence and testimony a single, fully staffed congressional investigation will be able to adduce. And it is certainly impossible to predict the impact such an investigation might have on the Trump’s standing, the upcoming campaign, or even possibly upon the now unlikely prospect of Trump being removed from office. But one thing is all but certain, the nation will be better served by such a congressional effort.