We believe the same about them. But will still vote for a Mormon. It has been said that if you replaced all the dim catholic pols with mormons, you would have laws much closer to the teachings of the RCC.
Look at it this way, you are going to support a Mormon either way, the question is, will it be Mitt Romney or Harry Reid?
Many analysts project the LDS to end up converting over to orthodox Christianity in due course on account of the core group being swamped by outsiders. This happened to The Worldwide Church of God ~ picked up too many converts through aggressive proselytization, and then when the founder passed on things began to change ~ now it's a mishmash of breakaway sects of greater or lesser fidelity.
Absent some other reason, schism is rarely permanent ~