There seems to be a minor movement in some parts of social media and left-leaning media to prevent Trump from taking office as President. Many have gone so far as to urge President Obama (who is not going to do any such thing) to declare Martial Law, or for the US Military to step in, in order to prevent Trump’s inauguration until Trump has been “cleared” of accusations of somehow being compromised by Russia. Such a proposal is not a simply call for a “pause until we can be sure” as some of its advocates propose, but would require suspending the Constitution, and ruling by force without even a fig leaf of legitimacy.
Supporters of such proposals may not realize it, but they are calling for a military coup.
Once Congress has counted and certified the results of a Presidential election, no one—not the current President, not Congress, not the Supreme Court, not the military—has the Constitutional power to prevent the new President from taking office:
[…] the President of the Senate shall, in the presence of the Senate and House of Representatives, open all the certificates and the votes shall then be counted; — The person having the greatest number of votes for President, shall be the President, if such number be a majority of the whole number of Electors appointed […] (Amendment XII—replacing parts of Article II, Section 1)
“Shall be the President” is pretty clear. While Amendment XX, Section 3, does mention the possibility of a case where “the President elect shall have failed to qualify”, that language does not provide any Constitutional exception for “we really think he’s a secret Russian spy” that some of Trump’s opponents seem to desire. The qualifications for President are clearly spelled out in Article II, Section 1, Clause 5, where it is stated that:
No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty five Years, and been fourteen Years a Resident within the United States.
Even if President Obama somehow lost his mind, and was to declare martial law to prevent Trump from being sworn in, the military would almost certainly ignore him. Military officers swear an oath to the Constitution, not a President. They have an duty to refuse to obey illegal orders. In any event, according to the Constitution, as of Noon on January 20th, Obama is no longer President. Full stop.
The terms of the President and the Vice President shall end at noon on the 20th day of January […] (Amendment XX, Section 1)
The standing on the capital steps, the ceremony of inauguration, the oath given by the Chief Justice, etc., is not required. All the Constitution says is that:
Before he enter on the Execution of his Office, he shall take the following Oath or Affirmation: — “I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my Ability, preserve, protect and defend the Constitution of the United States.” (Article II, Section 1, Clause 8)
Trump won the Presidential election, the Electors voted for him, Congress has certified the vote. It’s over.