Speaker Johnson’s observation that lawmakers cannot “wave a wand and just eliminate the special counsel” suggests that Jack Smith’s legislated armor is secure, at least until — if — President Trump regains the White House.

The decision by the speaker to rebuff pressure from his members — Representative Marjorie Taylor Greene, specifically — to move in the House against Mr. Smith was thrown into sharp relief by the Louisianian’s presence on Tuesday at Mr. Trump’s criminal trial at New York. That was a gesture of support from the lawmaker to the 45th president.

It did not, though, earn him a front-row seat. The man who is second in the line of succession watched from the overflow room. His defense of Mr. Smith’s independence — even as he excoriates the prosecutor for engaging in “lawfare” — comes at an extraordinary moment for his speakership. He last week survived a motion to vacate mounted by Ms. Greene. Mr. Trump last week offered a lukewarm endorsement, urging his party to stay the course, for now.         

The speaker explained to Politico that the insulation of the special counsel is “necessary” because the “Department of Justice — which is an executive branch agency — can’t necessarily, without a conflict of interest, investigate or prosecute the president who’s their boss.” Mr. Johnson practiced constitutional law, representing faith groups on religious liberty issues. 

Mr. Johnson’s flat “no” when asked if he would write legislation eliminating Mr. Smith’s job from appropriations bills was tempered slightly by his declaration that “there has to be accountability” and a reminder that “Congress has the power of the purse, of course.” That prerogative follows from the Constitution’s Appropriations and Taxing and Spending clauses, which say that “​​no money shall be drawn from the Treasury, but in consequence of appropriations made by Law.”

The helplessness of the House speaker in the face of what he calls a “terrible dereliction of duty with regard to the special counsel and how the whole system has been abused” is partly a feature of partisan politics. Any alteration to Mr. Smith’s appropriations would be required to pass the Senate, controlled  by Democrats, and be signed into law by President Biden. 

The budget Mr. Biden sent Congress projects only $4 million in spending on Mr. Smith’s efforts. A Department of Justice spokesman explained in a statement that the “figure is merely a placeholder for purposes of the FY 25 budget.” Last year, Mr. Smith’s efforts across his two cases totalled $29 million according to his own expenditures report.  

Ms. Greene is not the only solon wondering how to weaken Mr. Smith’s work. Representative Jim Jordan has engaged in a correspondence with Attorney General Garland wherein he has expressed “serious concerns regarding the potential for a coordinated effort between the Department and the White House to investigate and prosecute President Biden’s political opponents.”

If Mr. Trump, who calls Mr. Smith “deranged,” wins the White House, though, the constitutional conundrum becomes more acute. Mr. Smith is an executive branch employee — as, for that matter, is General Garland. The “provision” that Mr. Johnson referenced dates to the Clinton administration, and purports to establish that the “Special Counsel may be disciplined or removed from office only by the personal action of the Attorney General.” 

The regulation goes on to explain that the “Attorney General may remove a Special Counsel for misconduct, dereliction of duty, incapacity, conflict of interest, or for other good cause.” The constitutional ballast is a Supreme Court case, Morrison v. Olson. By a 7-to-1 margin, with Justice Antonin Scalia the sole dissent, the high court held that the Independent Counsel Act, a precursor to today’s special counsel regulations, was constitutional.

The Constitution, though, ordains that the “executive Power shall be vested in a President of the United States of America.” In vesting in a single individual, the president, the entire power of a branch of the government is constitutionally unique. In the other branches — the legislature and the judiciary — power is disbursed among more than one individual.

Special counsels — from Patrick Fitzgerald to Robert Mueller to John Durham to Robert Hur to David Weiss — have proved resilient to the powers of their respective chief executives. Yet it is possible that that should Mr. Trump retake the presidency, the attorney general he appoints could move to remove Mr. Smith. 

That chief law enforcement officer would be required to “inform the Special Counsel in writing of the specific reason for his or her removal,” though it is possible that the special counsel could challenge such a maneuver.

Mr. Trump could opt to wave another constitutional wand and direct the pardon power — criminal law Kryptonite for prosecutors — at himself. That is likely driving Mr. Smith’s rush to try Mr. Trump before November.