Congress finally heard from key Cabinet-level witnesses this week concerning the assault on the U.S. Capitol on Jan. 6. While the hearing shed light on events related to the attack, it also showed, once again, weaknesses in having Congress lead such an important public inquiry. Republicans on the House Oversight and Reform Committee demonstrated that many in the party are more interested in advancing falsehoods about the 2020 election and Jan. 6 than they are about getting to the truth.

Rep. Andrew S. Clyde (R-Ga.), for example, likened the image of rioters inside the building to “a normal tourist visit.” Rep. Jody Hice (R-Ga.) matched him, proclaiming that “it was Trump supporters who lost their lives that day, not Trump supporters who were taking the lives of others.” Rep. Paul A. Gosar (R-Ariz.) accused the Justice Department, without any evidence, of “harassing peaceful patriots.” Clyde also said it was a “boldfaced lie” to call it an insurrection — even though that’s exactly how the Trump Justice Department defined it in court proceedings. A handful of other Republicans spent the bulk of their time mischaracterizing the peaceful George Floyd protests of last summer.

But Republican obstruction is not the only challenge. The hearing also revealed more broadly that, even with Democrats presiding, Congress has so far failed to produce needed answers using traditional tools of investigation. There may be a vote as early as next week on legislation to form an independent commission to take over the job. Lawmakers will need to decide what powers such a body needs to succeed — and a properly designed commission can.

The past four years of congressional inquiries have shown how difficult it is for the legislative branch to pry answers out of the executive branch, or obtain testimony from former officials in a timely manner. Despite multiple subpoenas, two impeachment trials and lengthy litigation, the Trump administration successfully parried nearly every effort to obtain needed documents and testimony. Wednesday’s hearing on the Capitol attack demonstrated that such challenges to congressional oversight will by no means completely subside, even with a very different president in town.

Evidence of the Biden administration’s failure to cooperate was on display from the outset. In her opening remarks, committee chair Carolyn B. Maloney (D-N.Y.) announced that the Justice Department and FBI were stonewalling. “Neither DOJ nor the FBI have produced a single piece of paper in response to the requests sent by six House Committees, including this one, in March. Not a single piece of paper,” she openly lamented.

Maloney and her colleagues’ frustration would only grow over the next five hours. One of the key witnesses, former acting attorney general Jeffrey A. Rosen, refused to answer questions from both sides of the aisle, asserting that the Biden Justice Department had limited what he could discuss. “I guess you’re claiming executive privilege, even though you have not invoked executive privilege formally,” an exasperated Rep. Gerald E. Connolly (D-Va.) said after failed attempts to get Rosen to discuss Trump’s reported efforts to press the Justice Department to help overturn the election.

Although the Biden administration will never reach the level of antipathy to oversight that the Trump administration did, there were earlier signs that the Biden team is not eager to satisfy Congressional requests for information surrounding the Capitol assault. The House managers in the second impeachment trial of Donald Trump, according to reporting in The Washington Post, canvassed federal agencies for “additional details about what happened inside the Trump administration on and around Jan. 6, but made little headway.”

It is not just executive branch agencies that may try to stonewall investigators. House Speaker Nancy Pelosi’s latest proposal for a commission indicates that it may also want to look into factors such as the extent to which social media platforms contributed to the Jan. 6 events by propagating false claims and facilitating connections between individuals and groups that mobilized at the Capitol. The Facebook Oversight Board, a quasi-independent body established by Mark Zuckerberg, was refused when it requested information from Facebook on exactly these matters in deciding what to do about Trump’s account suspension. Imagine the legions of corporate lawyers that outside investigators will encounter if they make such requests of the tech companies.

How then might an independent commission be equipped to overcome these challenges where Congress has flailed?

A key facet will be sequencing. Congressional hearings are important tools with a long record of impact. But hearings with adversarial witnesses staged before a thorough documentary and testimonial investigation simply put Congress at a disadvantage. Such backward sequencing can spotlight obstruction but rarely yields facts and answers.

Bipartisan legitimacy and formidable resources are essential, but a commission could have an important advantage at the outset because it would be created by legislation rather than House or Senate rules. The legislation creating it could include special rules to empower it to obtain information and to litigate objections expeditiously. Congress has a menu of such options, and what it selects will say a lot about the seriousness of its effort and the prospects for the commission’s success.

Republican and Democratic bills to create a Jan. 6 commission suggest that it will most likely have subpoena power to compel the production of documents and testimony, but whether the legislation explicitly authorizes access to Trump White House records — which otherwise may be restricted under the Presidential Records Act — will be a test of its quality.

Because witnesses such as the former president and his advisers will no doubt challenge any subpoena — whether for official documents or documents held by third parties, like the Trump campaign — Congress could streamline litigation procedures. They could mandate, for example, that cases be heard by a three-judge panel with direct appeal to the Supreme Court. No more bouncing from trial court to appeals court and back down again. Relatedly, any litigation over documents governed by the Presidential Records Act could be governed by normal litigation rules, not the arcane process laid out in the act. It would be up to Congress to decide.

Once Congress is serious about establishing an effective commission, it can engage in deliberate efforts to make the stakes of the investigation crystal clear through its legislation. At some point, courts will be asked to balance the need for information against claims of executive privilege. Members of Congress and their staff with foresight know that it is now time to start building that record; for example, by making explicit the need for a full accounting in the text of the legislation.

The attack on the Capitol on was too important to consign to an ineffective investigation. The lies that animated the attacks remain active and influential — minutes before Wednesday’s oversight hearing, Rep. Liz Cheney (R-Wyo.) was ejected from her leadership position with the House Republicans for her repudiation of Trump’s false claims about the election. A 1/6 commission modeled on the 9/11 Commission, but specially equipped for the task at hand, offers the best solution to get to the truth and to harden our democracy against future attacks.