The commander-in-chief ought to fire Lt. Col. Alexander Vindman, who serves on the National Security Council, for rank insubordination. That is the key take­away from Tuesday’s hearings in the Democratic impeachment push.

Vindman, unlike other Democratic “star witnesses,” was at least on the July 25 phone call between President Trump and his Ukrainian counterpart, Volodymyr Zelensky, that set off the inquiry.

But Vindman was unreliable and had questionable judgment, according to his own outgoing superior, Tim Morrison, the National Security Council’s senior director for European affairs.

In fact, Morrison viewed Vindman as so untrustworthy that he opted to exclude him from his conversations with William Taylor, the senior US diplomat in Ukraine.

Vindman had an “unfortunate habit,” Morrison thought, of defying the sprawling executive branch’s carefully delineated chain of command. Vindman’s testimony vindicates Morrison’s dripping disdain for his former subordinate.

The officer, who testified that he has never spoken directly with the president, nonetheless admitted to advising Zelensky as to how to comport himself in his communication with Trump. Vindman testified that he did not have time to express his concerns directly to Morrison, but he apparently found the time to express his concerns to both Deputy Assistant Secretary of State George Kent and an unnamed individual in the intelligence community.

As The Federalist’s Sean Davis noted, it is about as plausible an interpretation as any that the nation is now slogging through this imbroglio because Vindman opted to work in tandem with a Deep State whistleblower to jump-start impeachment proceedings over a disagreement with a phone call’s ethics.

Suffice it to say, this is not how our constitutional republic is intended to operate.

Article II, Section 1, Clause 1 of the US Constitution is remarkably straightforward: “The executive power shall be vested in a president of the United States of America.”

Leftists may invariably decry constitutional law’s “unitary executive theory,” but as Attorney General William Barr noted last Friday, the notion that the president of the United States, and only the president of the United States, is responsible for carrying out “the executive power” of which Article II speaks is not a mere “theory.”

It is, as Barr said, a “description of what the Framers unquestionably did in Article II.”

When anyone else in the executive branch — be it Deep State, Shallow State or anywhere in between — attempts to undermine and thwart the president’s executive power, such action is not merely insubordinate or morally problematic. It is outright unconstitutional.

And as law professors Saikrishna Prakash and Michael Ramsey explicated in a 2001 Yale Law Journal article on the topic, the executive power incontrovertibly includes within its ambit all “residual” foreign-affairs powers, meaning all foreign-affairs powers not legislatively vested in Congress in Article I, Section 8.

To be sure, it is appropriate for top-level national security advisers to offer substantive opinions to the president. But Vindman has testified that he never even directly communicated with Trump.

If Vindman actually attempted to deliberately thwart or undermine the duly enacted president’s foreign policy agenda, then he was attempting to unconstitutionally carry out the executive power that the Constitution of the United States vests in the president of the United States alone.

Executive power, especially in the areas of foreign policy and national security, flows from the very person of the president. A lieutenant colonel has no right to interfere with the president’s discretion or attempt to undermine the president’s authority over policy disagreements — which is what the impeachment allegations amount to.

The straightforward remedy for Vindman’s insubordination ought to be his prompt dismissal from his perch on the National Security Council.

Josh Hammer is editor-at-large of The Daily Wire and of counsel at First Liberty Institute.