not so taft made an even bigger error as was thoroughly discussed in the blawgosphere in the last hours or so there is likely no person anywhere with standing to challenge the oath as void and in any case taking the oath is a condition precedent to executing the office it is not actually important that it be done a particular way it's a formality the presidency began at noon as everyone agrees taft in administering the oath to hoover used the word maintain instead of another word i think it was preserve there is no non crazy person who believes that hoover was therefore not actually president i would point you to a wikipedia essay that might help you relax but then i'd be in need of similar medicine hand