Fining federal officials circumvents the need to rely on the two other branches. It’s also more politically palatable than arrest and detention. Still, the question of whether Congress has the power to use its contempt power in such a manner has been murky, given that it has never been used before. Article I, Section 9, of the Constitution (known as the “bill of attainder” clause) prohibits legislative acts that single out one individual for punishment. When Congress has previously tried to withhold the salary of executive officials as an indirect way of removing them from office, courts have nullified such attempts as infringements on the president’s constitutional power to remove officers.

Even so, there are solid reasons to believe that Congress does indeed possess this power. The Supreme Court has consistently likened Congress’s contempt power to that of the courts. And since judges routinely issue fines to those held in contempt of court instead of jailing them, Congress too should be allowed to exercise the same power without violating judicial precedent. Second, although imposing fines on federal officials with the indirect motive of removing them from office can be unconstitutional, using the same means to achieve a different goal—namely, the disclosure of information to protect congressional investigations—is a different story. Congress has the power of the purse. Refusal to comply with its normal investigative proceedings will impose additional costs on congressional committees, and a fine aimed at recouping those costs can be justified under Congress’s prerogative to protect against the waste of federal resources.

Conor Friedersdorf: A Republican congressman’s case for impeaching Trump

If Congress has the power to directly fine contemners without going to court first, the procedure it should use remains unclear. One possible strategy is to borrow the legal procedures used by Congress in disciplining its own members. In the past, Congress has directly fined its own members at the conclusion of disciplinary investigations by either asking the Treasury Department to withhold a certain amount from their salary or asking the member to write a check directly to Treasury. In some cases, the fine that was assessed was commensurate with the cost of the ethical investigation.

The contemner or Treasury might well refuse to comply with these requests. If the contemner—Barr, for instance—is directly asked to provide a check and refuses, Congress’s only recourse would be to resort to the courts again, but this time with the much stronger claim that the contemner has misappropriated federal money, a serious crime on its own. Alternatively, Congress can ask the Department of the Treasury to withhold the contemner’s salary. Treasury has extensive control over the administration of the budget, and the department might well push back against Congress, much as the Justice Department does when it declines to pursue criminal action. Yet the case for executive discretion to ignore Congress’s demands will be much weaker. Justice enjoys the right to exercise discretion on whether to prosecute a criminal case, but Treasury’s refusal to follow congressional demands over the management of federal money will not have a clear nexus to any constitutional right that would counterbalance the power of the purse.

It remains to be seen how far Democratic leadership will venture down this unexplored path. But a new precedent could come into play again quickly. The House Ways and Means Committee has issued a subpoena for President Donald Trump’s tax returns. On Friday, Treasury Secretary Steve Mnuchin refused to comply.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.