No person shall be a Senator or Representative in Congress, or elector of President and Vice-President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof. But Congress may by a vote of two-thirds of each House, remove such disability.
Trump was found to be an insurrectionist.
Every member of the electoral college is obligated to take an oath to support the constitution. Any of them providing "aid and comfort" to insurrectionist Trump is barred from serving as an elector. They can't cast a vote for Trump, because doing so would be giving him "aid or comfort".
By the same argument, if he is elected, any state or federal civil or military officer who follows his orders would be giving "aid or comfort", immediately disqualifying themself from their position.