I wouldn’t worry. I doubt that he’s going to push a national blue law or require everyone to tithe to the LDS church (or even support something such as the Federal Marriage Amendment or the Human Life Amendment). And I suspect most Mormons, Romney included, regard polygamy as laughable nowadays. He also apparently could be quite liberal while governing Massachusetts (Mormons are quite conservative in their personal lives). I suspected he pretty much separated his Mormon oath from his gubernatorial duties. Why would it suddenly be different in the White House?
Cue spooky music...
Well, there is that old unilateral power thingy, Executive Orders....more scary music.