The simple RINO argument doesn't cut it with me since McCain was an even bigger RINO. As Chief Executive, I will take the business experience of Romney over the Club Member experience of McCain any day.
Whether McCain or Romney is a bigger RINO is a matter of opinion and I doubt you'd find anything approaching a consensus view on this forum about the matter. Each is a RINO. It's not like Republicans had a conservative choice among the viable candidates. If Romney had truly been a conservative, he could have drawn support away from McCain. Why would anyone who was offended by McCain's RINOism turn to Romney?
X - I pinged you on this because you had raised a similar point earlier.