I would have voted for any republican at the time. I was pissed about how Obamacare was shoved through and how he abused the office via EO. Nothing wrong with EO when used for executing law, but using it to get around congress is a deal killer. I like him as an individual but he shat all over that office constitutionally.
Romney seemed trustworthy, of good moral character, and pragmatic (gov experience). It was a no brainer. Now would he have abused the office as well? Not sure, but he would have been allowed to had he tried. Republicans today seem to have clammed up when Trump does it.