The dozens of newly elected Congressional Democrats sworn in last week are getting a lot of much-deserved attention. They are a diverse group who represent a wide variety of districts, but they are united by a common dilemma—how can junior members of a party that lacks control of the U.S. Senate or presidency make their mark with legislation?

Barring miracles, the sad fact is that over the next two years, they cannot.

True, Democrats will try to use so-called “must pass” legislation, like spending bills to keep the government open and reauthorizations of expiring popular laws, as a vehicle to do some good. But even advancing “must pass” bills is easier said than done. Just look to the current partial shutdown of the federal government with no end in sight for proof.

So are new members irrelevant? Are they just votes to prevent unchecked Republican rule? In other words, are the inspiring new members of the Democratic caucus to be consigned to insignificance?

That would be terrible, but it needn’t happen. There is something new members can do to demonstrate to their constituents, key activists, small-dollar donors, and in-district press that they are living up to their promises.

In a word: oversight.

“Oversight” sounds wonky—like the type of thing that leads politicians nowhere fast. And yet oversight can lead you to the presidency. It is no exaggeration to say that Harry Truman went from obscurity to the vice presidency (and then later the presidency) because of his superlative oversight work uncovering profiteering by military contractors in World War II. In reflecting on his work, Truman observed that “the power of investigation is one of the most important powers of Congress. The manner in which that power is exercised largely will determine the position and prestige of the Congress in the future.”

So what is this magical oversight power? The Congressional Oversight Manual, a project developed by the nonpartisan Congressional Research Service, defines the function of oversight as “the review, monitoring, and supervision of the implementation of public policy.”

That’s word salad. In ordinary English, oversight means investigating, both privately and, most importantly, publicly, anything that the government has done, is doing, or could be doing.

And since the actions of corporations invariably connect with public policy—indeed, that a business even becomes a “corporation” is itself a governmental act—oversight is even broader than that. Everything from Wall Street at the onset of the Great Depression to Big Tobacco to steroids and concussions in professional sports has been the subject of high-profile oversight.

And this isn’t investigating in the sense of what journalists or professors do—the people’s representatives in Congress have both power and democratic legitimacy that most so-called experts do not. Additionally, Congress can subpoena (i.e., demand the production of documents or witnesses) nearly anything or anyone, which is a big leg up on all other investigators.

And yet the fact that this enormous oversight power can be used for more than Benghazi-style efforts at gotcha politics is not widely known to new members of Congress. Indeed, 46 new House Democrats sent an astonishing letter to their party’s leadership in early December saying that while they “have a duty to exercise oversight over the Executive Branch, particularly when the administration crosses legal lines or contravenes American values, we must prioritize action on topics such as the cost of healthcare and prescription drugs, our crumbling infrastructure, immigration, gun safety, the environment, and criminal justice reform.”

While those issues are indeed pressing, it is a false choice to suggest Democrats must choose between substance and oversight. Investigations designed to expose, for example, the worst practices of Big Pharma or the Republican Party’s decades-long transfer of resources from infrastructure to tax cuts for billionaires are well-suited to building momentum for policy reversals. The same goes for oversight of human rights abuses by Trump’s goons on the border, the lies and corruption of Big Carbon, and all of the other substantive topics new members were elected to address.

As longtime progressive stalwart, Henry Waxman, the former representative from California, explained in his memoir, the fight against Big Tobacco was aided immeasurably by a series of high-profile oversight hearings that developed the now-iconic image of the lying corporate executive. The momentum created by congressional oversight was powerful, even if laws and regulations embodying the new consensus against tobacco took years to come to fruition. Overall, Waxman said, “proper oversight complements and strengthens the legislative process by identifying problems that may require new laws and by ensuring that existing laws are being executed as Congress meant them to be.”

In other words, despite its omission from Schoolhouse Rock’s “How a Bill Becomes a Law,” oversight is often a necessary antecedent to legislation. That’s why Rep. Alexandria Ocasio-Cortez (D-NY) was right to seek the power of subpoena for a special congressional committee laser-focused on climate change, and why it is disappointing that Democratic leadership did not grant the new committee this traditional power.

There are few substantive issues for which oversight of some combination of Trump, his administration, and corporate America would not help generate public understanding and consensus on a path to reform. For instance, as I have written previously, Democrats can pursue a politics of accountability on a broad array of “populist issues” through aggressive oversight, including issues of particular salience to rural and small-town America.

From Trump’s cozy relationships with private equity, hedge funds, and Big Carbon to children separated from their parents and put in cages, there is so much to oversee.

Some so-called moderates fear that oversight could lead to overreach, but with so much at stake the idea that Congress would be doing more oversight than warranted is simply impossible.

So what approach should new Congressional Democrats actually take to make the most out of their first few years in office?

Traditionally, much of the oversight power is done collectively via committees, which are assigned the task of writing our tax laws, overseeing foreign relations, or other subject-matter specific work. New members will be assigned to them, and the Congressional Progressive Caucus is working hard to get new progressive lawmakers to request assignment to the committees that oversee concentrated economic power like Financial Services (which oversees banking and housing), Ways and Means (which oversees taxes), and Energy and Commerce (which oversees much of the economy).

While new members rarely lead overarching investigations on committees, they can exert considerable influence on specific issues within the jurisdiction of their committees. That goes double for members with either demonstrated expertise (one can still buy a Consumer Law textbook written by California Rep. Katie Porter, for example) or with an obvious constituency-based interest in an issue (like Michigan’s tragic record of environmental injustice could be a priority for Rashida Tlaib).

But even if a member lacks superstar credentials, digging into the work, attending as many hearings as possible, and being willing to ask the questions corporate lobbyists and Trump administration officials don’t want to be asked can quickly elevate even the most anonymous new member.

On issues for which constituents are expressing great interest, members of Congress have enormous “convening authority,” even when an issue is outside the jurisdiction of any committee on which they sit. That means federal lawmakers have the power to solicit voluntary expertise shared by academics and think-tank experts on any issue under the sun. Expertise should not be something to be deferred to—the goal isn’t for members to outsource their positions to academics or think-tank staffers—but poked at, prodded, and considered.

Let’s imagine constituents are concerned about the closing of a Sears and the loss of jobs within their district. A member could call upon various experts on the impact of private equity and hedge fund strategies on workers and use that information to formulate a request for action by Treasury Secretary Steven Mnuchin—himself a former Sears board member and college roommate of the man who destroyed Sears, Eddie Lampert.

Once a critique of Sears, Lampert, Mnuchin, and Trump administration policy is formulated, a member has many options.

They can conduct an event in their district with activists, affected families, and the media to highlight their concerns. They can write letters—shared with journalists and activists via social media—to the profiteers, as well as to the businesses and investors involved who might not appreciate having made an enemy in Congress.

Members can build coalitions within Congress and with activist groups (unions, Netroots, civil rights groups, women’s groups, etc…) to highlight the destruction of Sears.

This model could be applied to a range of issues—from the influence of Saudi Arabian money on U.S. politics to police departments that have killed innocent Black men. Fixing deep-seated problems requires identification and public education—two tasks perfectly suited to oversight.

Vigorous oversight is what Congress must conduct in order to begin to fix the broken mess that is Trump’s Washington. To get elected, the newest members organized coalitions, developed bold messaging, and implemented contemporary digital electoral tactics—skills that can now be applied to the task of oversight.

In order to counterbalance Trump, the same grassroots activists who demanded Democrats run more inspiring candidates everywhere must now demand that the new members conduct oversight of governmental and corporate misconduct as boldly and energetically as they campaigned.