Romney was never a Democrat was he?
Not to my knowledge.
Romney was a liberal independent, however, and at one time or another betrayed the Constitution and spoke out against Reaganism, the Contract With America and the Republican Party. Not to mention supporting Roe v Wade, gun control, gay rights and promoting nationalized health care. But of course, evberything changed when Romney decided to run for POTUS in 2005.
I don’t remember Reagan engaging in those politics as a Democrat or a Republican. Do you?