What do you think would have been the result of the 2012 presidential election if Romney had campaigned on his record?It's an important question because it has a clear, certain answer: that Romney could not have been nominated by the 2012 Republican Party. He would have been knocked out, receiving Hunstsman-level support if that, depending on whether "campaigned on his record" meant only those things or extended to guns and abortion.
* Said that he did his job of creating wealth for stock holders at Bain even though people lost jobs and that he would do his job of president to get more people working.
* Stood behind Romneycare.
* I think he was for cap-and-trade before running for president.
* Proposed tax policies that actually added up.
A candidate Romney who flipped (back) on these things after winning the nomination by sticking to the GOP platform would have risked a horrible mess...some Republicans would have stuck with him, but the odds are very strong of a major, debilitating party revolt, with Romney reduced to winning Utah and maybe a handful of others.
I'll add one more. Forgetting about the specific issues, what about a supremely skilled candidate Romney who was able to fully pull off the "moderate technocrat" image that was his best bet? My guess is that at best it gets him a couple of points, leaving him still a solid loser. Indeed, I haven't looked post-election but in the fall if I recall correctly his reputation among voters was, indeed, moderate technocrat. The bottom line is that the out-party candidate's image just doesn't matter very much in presidential elections when there's an incumbent on the ballot.
But the key thing here is that parties really are not going to nominate someone who opposes their consensus positions. Just not going to happen. And the 2012 position on health care, taxes, and climate didn't allow for Romney to deviate at all.