I think this is a sad mischaracterization of the purpose that general elections with limited viable competition serve. It isn’t an American Idol contest for alabaster sainthood.
I am not Catholic, but this is a place where I’m seeing conservative Catholic pundits make sense: Limit evil in whatever way possible.
No, it isn't, but at the very least, we should expect (and demand) that our nominee has a demonstrated track record of supporting at least some of our values.
For the life of me, I can't find anything in Mitt Romney's record to indicate that he's ever shared any beliefs or convictions with center-right Americans, let alone, solid conservatives.
On the other hand, if I were a liberal Democrat, I'd find quite a bit to like about his record, and might even cross the aisle to vote for him.