Acting Idaho Gov. Janice McGeachin observed the 24th anniversary of the bombing at Oklahoma City on Friday by encouraging the ideology that sparked it.

On April 19, 1995, Timothy McVeigh detonated a truck bomb at the Alfred P. Murrah Federal Building, killing 168 people and injuring more than 680. It remains the nation’s deadliest act of domestic terrorism.

McVeigh justified his actions by saying he hoped to “wake Americans up to the tyranny of government.”

His ideological heirs are a group of self-styled extremists calling themselves the Three Percenters — militia-minded types who have declared the same credo: “When tyranny becomes law, rebellion becomes duty.”

In other words, they alone define when the government has become tyrannical; they alone decide when to take up arms against it.

Among that group would be Eric Parker of Hailey, who struck a sniper’s pose from an overpass, aiming an assault rifle toward law enforcement officers during the 2014 Bunkerville, Nev., standoff between federal agents and public lands grazer Cliven Bundy. Parker served 18 months in federal custody.

Although some need no encouragement toward insurrection, McGeachin offered it anyway by presiding over a rally outside the Idaho Capitol.

Perhaps the most egregious rhetoric came from Rep. Chad Christensen, R-Ammon, who observed “the greatest enemies of the Constitution are not to be found in the sands of some far-off land, but rather right here at home.”

But Chistensen is merely a freshman House backbencher who lacks the ability to compose a single original sentence. He apparently lifted his remarks wholesale from anti-government activist and radio host Adam Kokesh.

McGeachin, on the other hand, is the duly elected lieutenant governor, who serves as Idaho’s acting chief executive whenever Gov. Brad Little leaves the state.

When he did so briefly Friday, McGeachin used her fleeting moment of authority to administer an oath of office to the Three Percenters.

But not just any oath of office.

She read from the oath administered to National Guard members, in which they swear to “support and defend the Constitution of the United States ... against all enemies, foreign and domestic, ... that I will bear true faith and allegiance to the same. ... So help me God.”

The Three Percenters hold no military or civil office in the state.

Exclaimed Idaho’s acting chief executive: “Hallelujah.”

Hallelujah, indeed.

McGeachin conveniently omitted most of the text — including a critical clause of the oath that obligates a person to “obey orders of the president of the United States and the governor of the state of Idaho.”

Let that settle in. The acting governor of Idaho on a day of unmistakable significance edited a service person’s oath of office in such a way to convey the state’s approval toward rising up against “enemies, foreign and domestic” without answering to civilian authority or any outside authority.

Who knows who was listening or what lesson they learned?

One can only hope they take McGeachin no more seriously than she deserves to be — but in this environment, that’s more of a prayer than a realistic expectation.

Idaho is no stranger to such outrageous official misbehavior. A quarter-century ago, it was the late former Congresswoman Helen Chenoweth-Hage, who responded to Oklahoma City by criticizing those in Congress who didn’t understand the grievances among anti-government activists.

But this is becoming a pattern for McGeachin. Earlier this year, she made a point of showcasing her support for Boundary County resident Todd C. Engel — who is serving 14 years in prison for brandishing an assault rifle at federal officers at Bunkerville — with two Three Percenters.

As the Post Register’s Bryan Clark noted, at least one of the body guards who accompanied her to a public television debate last fall was wearing a Three Percenter tattoo.

What she does on her own time and with her own office is a matter between McGeachin and the voters.

But only Little can extend the prestige of his office to her. Any time Little leaves the state, the powers and duties of the chief executive transfer down the chain of command. First in line is Idaho’s No. 2.

Obviously, McGeachin has proved herself unfit.

So what does Little have to say about this? It’s been nearly a week since the Statehouse rally. Does McGeachin speak for him?

If not, why has he remained silent?

More than that, Little needs to guarantee there will be no recurrence.

Even if it means limiting his travel out of state, Little cannot leave Idaho in McGeachin’s treacherous hands. — M.T.