General Pace - you have the power to fulfill your responsibility to protect the troops under your command. Indeed you have an obligation to do so.Now, seeing as Article II, Section 2 of the US Constitution makes clear that "The President shall be Commander in Chief of the Army and Navy of the United States" it is not possible to relieve the office of its command whilst allowing the holder of the office to remain President.
- You can relieve the President of his command.
- Not of his Presidency. But of his military role as Commander-In-Chief.
- You simply invoke the Uniform Code Of Military Justice.
If you're President you're Commander-in-Chief, you cannot be President and not be unless there is a military coup, which, as much as they may think they're not doing, is what the Huffington Post is actually calling for. After all, calling for the highest ranking officer below the US President to arrest the President and take control of the Armed Forces cannot be described as anything other than a coup.