When I think of Ted Kennedy and Jimmy Carter I don't think "Catholic" and "Baptist", I think "drunk murderer-traitor" and "incompetent Arabist-traitor." They certainly don't cause me to think differently about their professed relgions.
~”They certainly don’t cause me to think differently about their professed relgions.”~
Me neither, because I have context that tells me that they are exceptions, and not the rule.
Many people have no such context about Mormons - a President Romney would be their first exposure. If they don’t like his politics, will they refuse to listen to the tenants of the faith he embraces? Some will, I think. That does concern me.