Charliehall.
1) Actually I am sure as a statistician you can understand how the slightest nuance can have untold ripple effects, as such I can try and explain to you some slight nuance that apply in this case.
Mitt Romney was not running based on his faith nor was he asking for support based upon his faith, rather he was running on a set of policy positions.
Voting for Romney was not a vote in support of his personal faith, rather it was a support of his public policy positions.
Attending the parade is for the sole purpose of showing solidarity with the horrible aveira represented.
2) On a strictly halachic basis assuming that Mormon ideology acknowledges HKB”h as being the “head of the “triangle” there is plenty of halachic basis that states polytheisim (shituf) is not assur for a non-jew.