“This is an oath taken by Romney in the mormon temple. Are you certain that if Romney took the presidential oath of office it would supersede this oath?”
What you fail to understand, greyfoxx, is that the Kingdom of God and Zion are spiritual organizations, referring to the LDS Church itself. This oath has nothing to do with politics or nations. It means being willing to serve in the Church and help to build it up.
Therefore, to ask if the oath of office would supersede this oath is a moot question. They are not incompatible; Romney is perfectly capable of fulfilling both simultaneously.
You read the oath through the lens of your own interpretation, rather than that of those who actually take it. This is a mistake.
Nice try.