I the OTL, there are many who became Conservatives who were once Liberals, and many Liberals that were once Conservatives. So who could have been a Liberal or Conservative given different circumstances?
Some that come to mind (albeit I don't know the circumstances to keep them to their original ideology):
Ronald Reagan
New Deal Democrat turned Goldwater Conservative after reading "Witness" by Whittaker Chambers.
Hillary Clinton
Loyal Goldwaterite who became Liberal over the decades.
Oliver Stone
I was surprised by this fact when I was reading a book on the Baby Boomers. Apparently, during the early 60's Stone considered himself a very mundane, loyal Republican who wanted Goldwater to win in '64 and all that.