President Trump is unlike any other president in American history. His coming confrontation with Congress will be different too.

Trump plays by no rules—which means that House Democrats cannot afford to play by the old rules if they hope to obtain likely damning evidence of corruption that Trump will fight to suppress.

The response of presidents to congressional investigations has seldom been cheerful. But after the 1994 election, the Clinton administration produced two million pages of documents in response to more than 1000 subpoenas issued by House Republicans investigating alleged misconduct by the Clinton administration and the Democratic Party. Three of Clinton’s chiefs of staff testified before Congress, as did four White House counsels, the chief of staff to the vice president, the chief of staff to the first lady, and an assortment of officials with “deputy,” “assistant,” or “deputy assistant” in their titles. A total of 134 Clinton administration officials testified in public hearings on alleged misconduct and 141 Clinton administration officials spent 568 hours in staff depositions.

The Bush and Obama administrations did not follow the Clinton administration’s example of grudging obedience to lawful congressional subpoenas. Instead, they lost their respective battles with Congress over subpoenas, but won the war against congressional oversight.

The pattern of the Bush and Obama administrations’ fights with Congress over congressional investigations is familiar. Congress demands documents and testimony first by letter and then by subpoena. The administration claims that the investigation is motivated by political partisanship, which is at least partly true but irrelevant. The administration argues that the investigation is outside of Congress’s investigative powers and that the administration’s deliberations over the policies or actions under investigation are privileged, and refuses to produce the subpoenaed documents or to allow administration officials to testify. Congress refers criminal contempt charges to the Department of Justice, which refuses to prosecute. Congress then files a civil lawsuit to ask a judge to order that the administration provide the subpoenaed documents or testimony.

Finally, Congress wins because congressional investigative powers are broad and executive privilege is narrow. But by then the clock has often run out, and other investigations slowed to a crawl because Congress can only pick so many such fights with the president at the same time.

Trump, of course, will be even more openly obstructionist, and promises a “warlike” response to congressional investigations. His allies openly proclaim that his strategy is to hinder and delay congressional investigations until after the 2020 election. The administration’s use of frivolous arguments and dilatory legal tactics will only be limited by their lawyer’ risk appetite for court sanction.

House Democrats will investigate controversial policies and actions by the Trump administration, of which there are many, as well as the incompetence and casual venality of many administration officials. Such investigations have long been the bread and butter of congressional oversight.

Those investigations will be for relatively low stakes, at least to Trump, who feels little loyalty to anyone apart from his own family, if even to them, and is lightly invested in policy. A tweet or two often explains the entire rationale for the administration’s most controversial policies. There are few if any internal memos or emails for investigators to find because administration officials first learn of policies from Trump’s tweets.

Investigations of corruption, on the other hand, will be for very high stakes. Trump will fight those investigations tooth and nail.

Federal and state prosecutors already have most and maybe all of the evidence of corruption that congressional investigators will seek. The administration will do everything possible to block the release of that evidence to Congress or to the public.

But House Democrats have a powerful, and long dormant, tool at their disposal as they retake control: they can enforce subpoenas to obtain documents and testimony without the help of prosecutors or judges. The House and the Senate have inherent power to jail a contemnor until the contemnor provides subpoenaed documents or testimony, similar to the civil contempt power that judges use to enforce obedience to court subpoenas or orders.

Congress has rarely exercised that inherent power since the Civil War, and not at all since 1935. Since Americans associate the power to incarcerate with courts, Congress has called in prosecutors and judges to enforce congressional subpoenas to give themselves political cover.

The politics may have changed. To many Americans, especially Democratic voters, the reluctance to use legal powers to check Trump will appear timid, not judicious. And there are checks against abuse of Congress’s inherent contempt power. Anyone jailed for disobeying a congressional subpoena will have immediate recourse to the courts by a habeas corpus proceeding. Any incarceration that is not legally defensible will be very brief.

Trump will decry any investigation as a partisan witch hunt by House Democrats and a dictatorial abuse of congressional powers, as will the right-wing media. But they will say the same no matter how judiciously—or timidly—House Democrats proceed. Many Americans are numbed to Trump’s bombast.

The British parliament recently used inherent contempt to obtain internal Facebook documents over Facebook’s vigorous objections. The executive of a company in a lawsuit with Facebook had copies of the documents. The documents were subject to a California court’s protective order, but the executive quickly provided the documents to parliament when threatened with jail. Facebook’s legion of lawyers was powerless to prevent the disclosure.

The documents revealed that Facebook collected sensitive user data and provided the data to favored companies. The British press roundly criticized Facebook for misuse of user data and for resistance to proper government scrutiny. Parliament won praise for bold action. Facebook’s complaints that parliament’s tactics were sketchy won little sympathy.

The same may be true here. Americans may pay more attention to what congressional investigations find than to how Congress obtained the evidence.

Even if they use their inherent contempt powers, it will probably still be difficult for House Democrats to win quick compliance with subpoenas of administration officials. Much of the evidence of possible corruption, and maybe the most damning evidence, will be held by private parties, however, and may be beyond Trump’s power to suppress.

The administration has until now ignored the demand by House Democrats for information about the federal government’s lease of Washington’s Old Post Office. Trump and his older children converted the historic landmark into Trump International Hotel. With the power of the majority, House Democrats will now subpoena the same information, which the administration will refuse to provide on some thin argument. The hotel itself, however, has the same information and no legal excuse, however thin, not to comply with a subpoena.

House Democrats will demand that the IRS provide Trump’s tax returns. At Trump’s direction, the IRS will refuse despite an express statutory command to do so. But the returns and even more revealing financial information are likely available from Trump’s business, as well as from Deutsche Bank and other financial institutions that made loans to Trump.

An employee of Deutsche Bank with control of subpoenaed documents, like the executive with control of Facebook documents subpoenaed with Parliament, may see little appeal to jail time for disobedience of a congressional subpoena. And Trump’s pardon power cannot release from jail anyone held to enforce obedience to congressional subpoenas.

If House Democrats aggressively use their own inherent contempt power, then there may be little Trump can do to suppress information controlled by private parties.

As to the politics, House Democrats may better risk appearing dictatorial than to appear feckless.