Given that:
1. I have always believed that Romney went to washington specifically to stick a knife in Trump's back
2. The question of a vote on impeachment is not one of religion, it's a question of law
Point one makes me question whether Romney truly had a strong opinion on the point of law. Point two tells me that he was trying to hide behind his religion, not that his religion informed his vote. If his religion had an impact on his interpretation of the Constitution, then he violated the oath he took upon entering office. If his religion required the violation of that oath, then he should not have sworn it in the first place.
So basically, I don't know whether Romney is sincere in his faith and I don't care. I do think that his actions fulfilled the prediction I made several years ago, which causes me to increase my certainty in my understanding of his motives. And again, I think he invoked religion as a fig leaf - to try to retain some political support from religious people in general and Utah Mormons in particular.
So it's hard for me to view his actions here as motivated by the singleminded pursuit of truth with disregard for worldly consequences. But that does not bear on whether he believes in his religion.
And there are questions of how well we understand our own biases and motivations laced throughout. How does that impact Romney's decision-making, how does it impact my evaluation of Romney.