When the Republican-controlled House threatened Obama Attorney General Eric Holder with contempt for refusing to respond to a subpoena in the “Fast and Furious” scandal, he was able to laugh it off. It was like the joke about the dispute between God and the devil over the boundary between heaven and hell. When God threatened to sue, the devil wryly replied, “Where are you going to get the lawyers?”

Now House Democrats are on the verge of voting to hold Attorney General William Barr in contempt for failing to provide them a fully unredacted copy of the Mueller report. Barr has already legally given them transparency beyond what the law requires. For Barr to go further would violate the law that protects confidential information such as what comes from grand jury proceedings.

The initial distinction between the Holder contempt matter and what may happen to Barr is that the former involved hiding from Congress information about lawbreaking by the government, while the latter would require Barr to violate the law to comply with the subpoena issued by Democrats under House Judiciary Committee Chairman Jerry Nadler. That’s an important distinction for observers who aren’t so overwhelmed with Trump Derangement Syndrome that they can think clearly.

Another major distinction is that the threat to hold Barr in contempt could boomerang back at House Democrats with two potential criminal charges. The crime of solicitation involves soliciting another person to commit a crime. The crime of extortion may involve using the threat of prosecution to coercively dispossess what is owned or possessed by another. Extortion initially was a crime that applied to public officials only.

The DOJ may think both of these criminal charges should apply to the requests and demands made to Barr to commit a criminal act itself. Nadler and his Democrat colleagues will need to lawyer-up if the DOJ wants to pay hardball here.

The threat to hold Barr in contempt presents interesting questions about Article I of the Constitution, which vests all legislative powers in Congress. Based on common law precedent, but not expressly stated in Article I, Congress may issue subpoenas. Such subpoenas may be issued for a legislative purpose, unlike other searches and seizures of persons or papers that require probable cause. And, the authority to issue subpoenas implies a power to hold someone in contempt for refusal to comply.

The question, then, is it a valid legislative power or purpose to require someone to commit a crime to reply to a congressional subpoena? Barr and the DOJ have presented the clear state of the law, which is undisputed, that the grand jury information in the Mueller report is confidential under law. It is easy to conclude Congress may not order anyone — particularly the United States attorney general — to commit a crime by disclosing that information.

This also sets up a separation of powers dispute about whether Congress may override the laws it passed to obtain information held by the executive branch. While courts are reluctant to weigh in on separation of powers disputes, the landmark case Marbury v. Madison provides precedent for the court to decide as the arbiter of how the law should be upheld and enforced.

If the DOJ were to decide to play hardball with Nadler and his colleagues, and bring a case for extortion or solicitation of a crime, both of which charges involve crimes of words, the Democrats would certainly claim they have immunity under the Speech and Debate Clause of the Constitution. They “shall not be questioned in another place,” such as a court of law, for their statements made in the conduct of their legislative duties.

This important immunity against arrest of the duly elected representatives of the people is a protection of liberty that is the raison d’etre for the separation of powers. This constitutional privilege, however, is not designed to encourage dystopian mob rule, and therefore has reasonable limits.

For example, the Supreme Court in Gravel v. United States noted that “speech, voting, and other legislative acts [are] exempt from liability that might otherwise attach,” but that does not privilege members of Congress “to violate an otherwise valid criminal law in preparing for or implementing legislative acts.”

Since the acts of voting to subpoena documents and voting for contempt are indeed legislative acts themselves, the DOJ must distinguish those from what could be criminal conduct of soliciting Barr himself to commit a crime, or extortion by using the threat of contempt for refusing to commit the crime. The latter may be deemed the crimes “in preparing for or implementing legislative acts.”

Bill Barr’s composure during the post-Mueller report circus shows that he’s got sand. I would not be surprised if his DOJ under the master counter-puncher, Donald Trump, decided to get aggressive with Nadler, whose claim of a constitutional crisis could come back to bite him.