Amendment XXVIf the president-elect couldn't or doesn't show up to be inaugurated, I would have to think the Supreme Court would have to get involved. The Constitution seems to be silent on the matter. Probably what would happen is that the vice president elect would take the oath as acting vice president and then the lawsuits would fly.
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Section 4. Whenever the Vice President and a majority of either the principal officers of the executive departments or of such other body as Congress may by law provide, transmit to the President pro tempore of the Senate and the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office, the Vice President shall immediately assume the powers and duties of the office as Acting President.
Thereafter, when the President transmits to the President pro tempore of the Senate and the Speaker of the House of Representatives his written declaration that no inability exists, he shall resume the powers and duties of his office unless the Vice President and a majority of either the principal officers of the executive department or of such other body as Congress may by law provide, transmit within four days to the President pro tempore of the Senate and the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office. Thereupon Congress shall decide the issue, assembling within forty-eight hours for that purpose if not in session. If the Congress, within twenty-one days after receipt of the latter written declaration, or, if Congress is not in session, within twenty-one days after Congress is required to assemble, determines by two-thirds vote of both Houses that the President is unable to discharge the powers and duties of his office, the Vice President shall continue to discharge the same as Acting President; otherwise, the President shall resume the powers and duties of his office.
Some states don't allow you to change the person on the ballot. It depends on the state. Some states don't allow changes within days, some weeks, some months. The ballots are usually finalized after late summer runoffs. There are 50 individual state elections and they all have different rules, different standards. The only thing they have in common in is the election date, and that isn't even completely true because in 11 states you can vote right now.
posted by Fairchild at 7:21 PM on September 25, 2008